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Showing most informative content since 02/23/2013 in all areas

  1. 35 likes
    Dinosaur skin are a highly sought-after fossil. The ones usually available to collectors are Edmontosaurus skin impressions from Lance, or Hell Creek Formation, and they aren't as rare or expensive as you might expect, fetching up to 100-200 USD per inch depending on quality. However, it is easy to mistake a bumpy piece of rock, mud sediment, septarian nodule, concretions, or a coral fossil as dino skin. Right now there are at least several of such on our favorite auction site. Here are examples of fossils/pseudofossils mistaken as dinosaur skin: And here are real Edmontosaurus skin impressions: Positives: Negatives: So how do we tell real skin impressions from misidentified ones? Honestly, it isn't always easy, but here are four basic guidelines. 1) Skin impressions come as negatives or positives. If it comes with both, even better! 2) Skin impressions are rarely ever a complete piece by themselves(not the way a tooth or an ammonite is). Instead, skin impressions are often fragments, or look like they are broken off from larger chunks 3) There should be a uniform shape to each individual scale/osteoderm. Refer to the negative pictures above 4) Most skin impressions come from South Dakota. If you get another locality, be on extra alert - it's either another species(and thus very expensive), or misidentified If in doubt, ask the forum before purchasing. There are plenty of experts here glad to help. Have fun shopping!
  2. 29 likes
    The popular collected trilobite Phacops rana is well embedded in literature for over a hundred years. Then in 1990 it was renamed Eldredgeops rana. A lot of collectors did not understand why the name change and I would like to attempt to clarify why the change. The purpose of this post is to point out the differences I have observed between Phacops and Eldredgeops and explain why "rana" is an Eldredgeops and not a Phacops. The literature on phacopid systematics is in a mild state of disarray. Authors have built on the errors of previous authors. There is no good English diagnostic description of Phacops based on the type species of P. latifrons. This has resulted in different English definitions of Phacops and causing much confusion. I'll first start with a review of what are the types and where they come from. Types: 1. Phacops Emmrich (1839) described the genus Phacops based on the species Calymmene latifrons Bronn, 1825 from the Middle Devonian (Eifelian Junkerberg Formation), Gerolstein, Germany. Because the holotype has been lost, it has not been clear what to base the diagnosis of Phacops on over many years. Then Struve (1982) illustrated topotype material but it was Basse (2006) who designated the neotype of Phacops latifrons. Now there is a definitive specimen to base the description of Phacops on. I have been fortunate to have traded for a topotype cephalon of Phacops latifrons Definition of topotype - a specimen of a species collected at the locality at which the original type was obtained 2. Eldredgeops Stewart (1927) described Phacops rana milleri from the Middle Devonian (Givetian Silica Shale), Sylvania, Ohio. Struve (1990) designated Phacops rana milleri the type species of Eldredgeops. I believe the different subspecies of Phacops rana described by Eldredge (1972) are different species and are assigned to Eldredgeops. I will to refer to these different species Eldredgeops as the "rana group" as a way to simplify the naming of all the different species. Observed different characters: I do not know what are the diagnostic generic features of Phacops or Eldredgeops. All I'm doing is listing some of the differences I have observed between these two trilobites to show they are different genera. Pictures of Phacops latifrons and Eldredgeops milleri are below for comparison with numbers pointing to the different features. Pictures of Eldredgeops rana from New York are also included so one can compare the two species of Eldredgeops and see how they differ. Now for the first time a topotype specimen of Phacops latifrons is compared with a topotype specimen of Eldredgeops milleri. There is no place in the literature where this is done. 1) marginulation - a raised ridge along the ventral margin of the cephalon. It is present in the "rana group" and absent in P. latifrons. It has been used by Flick and Struve (1984) as a diagnostic feature for their tribe Geesopini. Note: The value of this feature for the tribe has been questioned. McKellar and Chatterton (2009) state "This feature has never really been evaluated from a phylogenetic standpoint" 2) The post ocular ridge is prominent in P. latifrons and is absent in the "rana group" 3) The palpebral area is smaller in P. latifrons than in the "rana group" 4) The palpebral lobe is smaller in P. latifrons than in the "rana group" 5) The number of eye files in the "rana group" ranges from 15-18. E. milleri has 18 and E. rana has 17. In P. latifrons the number of eye files is 14-15. The topotype specimen has15 files with a maximum number of 5 lenes. 6) The maximum number of lenes in P. latifrons is between 4-5; E. milleri has 8-9; E. crassituberculata has 6 or less; E. rana 6 Note: Both P. latifrons and E. norwoodensis from the Cedar Vally Formation have the same number of files (15) in the eye. One might determine that this would result in the palpebral lobe being the same size but this does not happen. P. latifrons is smaller than E. norwoodensis. So there is some other factor affecting the size of the palpebral lobe. 7) The subocular pad is present in P. latifrons and absent in the "rana group" 8) The glabella is inflated and its front wall varies from vertical to slightly overhanging the anterior border in the "rana group" and is not as inflated in P. latifrons 9) Lateral preoccipital lobe is round in P. latifrons and is rectangular in Eldredgeops. To summarize the differences: Eldredgeops is marginulated, has an inflated glabella, a rectangular lateral preoccipital lobe, the palpebral area and palpebral lobe and larger than P. latifrons, and does not have a post ocular ridge and subocular pad. Phacops latifrons is not marginulated and the glabella is not inflated, has a post ocular ridge and a subocular pad and a round lateral preoccipital lobe. the palpebral area and palpebral lobe are smaller than Eldredgeops. Other observations: These two genera occur in different time periods. Phacops latifrons is in Middle Devonian Eifelian and Eldredgeops milleri is in the Middle Devonian Givetian It appears all the phacopid of North America disappear at the end of the Eifelian and Eldredgeops migrates from the Old World fauna into North America in the Givetian. Eldredgeops does not evolve from any North American phacopid. Eldredgeops is in the Tribe Geesopini and all the genera of this tribe have not been validated. If these genera are reexamined, it is possible that Eldredgeops could become a junior objective synonym of an another genus in the Tribe Geesopini. Hopefully, now collectors will understand the differences between Phacops and Eldredgeops and why the "rana" group is now referred to as Eldredgeops.
  3. 26 likes
    FOUND IT! It was in Seilacher's Trace Fossil Analysis:
  4. 24 likes
    A Beginner's Guide to Fossil Hunting So you think you want to fossil hunt? Start your journey on the internet. 1. Do a search for fossil websites and fossil documents for your state, region, locality. You should be able to come up with PDF's of local fossils with pictures and often a “basics” guide for your area. Hopefully you will find fairly local websites that will have pictures of local fossils and perhaps even where to find them. Familiarize yourself with what you are likely to find, and remember that the fossils with probably be in matrix (rock) and you will only find a small portion peeking out. Check to see if you have any local museums, etc. that have fossil collections for public viewing - check them out. This will also teach you what kind of fossil hunting you will be doing – beach combing, sifting for sharks teeth, breaking shale, or walking road cuts and dry washes. 2. Do an internet search for the GEOLOGIC MAPS for your area. Most of the time, these will be online through a government or university office. If you can't find them on the internet, call or stop by your local government office that functions for “planning and zoning” or perhaps “environmental services”. These maps are usually accessed by well drillers and companies that install sewer systems. Ask them for the geologic bedrock maps for your area. Many times they will either just give them to you or there is a nominal charge. These maps will give you the names of the bedrock formations in your area, and if you are lucky, will even tell you which bedrock is in which time period (Ordovician, Silurian, Devonian, etc.), if it is fossiliferous or not and maybe even what fossils have been found there. If not, you can simply research the names of the formations and find that information out yourself. If you are interested in geology as well, go to your local library or search the internet for geology books for your area that are written for the lay person, a good series in the United States is the “Roadside Geology for...”. But your geologic formation maps will give you what you need to know for fossil hunting. 3. Find a road map of your area (Google Maps) and approximately match up the road map with the fossiliferous areas shown on the geologic map. You now have a general area to hunt and know what fossils you are looking for. If you are handy with the internet, go to Google Earth and start your search with a virtual drive of the roads you think will be most productive. You should be able to see the road cuts, rock formations, dry creek beds, creeks and rivers, beaches, etc. along the road as well as whether or not there is potentially safe parking near the site. If you can master this, it will save you hours of time and $ in gas! 4. Do a search for local rock, mineral and fossil clubs in your area. Mentoring from experienced members is invaluable! And they may even have field trips and digs that you can attend! While you are at it, see if there are any fossil parks near you. 5. Your first hunt - what do you need? Something to carry your fossils in and drinking water. Tip: take an empty bottle, fill it half full with water and freeze it. Before you leave fill the rest with water and you will have ice cold water for several hours. Everything depends on your area and comfort level and if you are hunting alone or with children. A bag, pail or backpack with a handle are all good for carrying your finds. Bring something to drink to stay hydrated and something to eat if desired. A sieve if looking for sharks' teeth, etc. in creeks and a hammer to knock away excess matrix if desired. If you are taking children, make it FUN! Depending on the age of the child, they can actually do all the research for you and plan the trip! Think picnic with kids. Drinks and finger food. They should have their own bags. A magnifying glass would be good. Depending on your area and the time of year, sunscreen, insect repellant, TP, band aids, water shoes, whatever is appropriate. And personally, I recommend a whistle for every member of the party in case you get separated – 3 short blasts for an emergency (I'm lost, sprained ankle, I'm scared.) and 1 if you found a patch of fossils - they will often be in groups. Practice with the whistles before the hunt, not in the car as you are going to the hunt. :-D Bring home anything that looks like it may be a fossil, you just never know. The first time I took my granddaughter out on a hunt the very first thing she found I couldn't identify – rock or fossil? It didn't look like anything I had ever found before, but it was interesting. I ended up posting it in the Fossil ID section and it turned out to be a stunning example of a fairly rare for this area Ordovician Halysites Coral (Chain Coral)! Beginner's luck! And she was hooked! 6. Identifying your fossils. If you followed this format, you have probably downloaded several PDFs of common fossils for your area. Compare what you have found to the images. Still not sure? Get as close as possible and then do a Google Advanced Image search here (just bookmark it): http://www.google.com/advanced_image_search?hl=en When you see an image that looks close to your find, click on it and go to the site where it was found and read a little about it. Not all images will be accurate! Still not sure? Take a good quality picture of it from several sides (Please use a ruler, tape measure, coin, whatever, for size approximation.) and post it in the Fossil ID section of thefossilforum.com, along with... a. Approximately where you found it, a park, a part of the state, whatever. b. What you think the geologic formation is – that's what your map is for, and c. The time period (Cambrian, Ordovician, Silurian, Mississippian, etc.) you think it is from. Then wait patiently and see if someone is able to identify it for you. Please wait at least 24 hours before you thank the people who have tried to identify it for you, because the first IDs may not be correct and not all members get on every day. It took me almost a year to figure this out – slow learner! I hope this helps you jump start your own Adventures Fossil Hunting! Bev :-D Okay Guys & Gals, I just compressed everything we had on that recent beginner's topic into one post, added a few things and some pictures. I tried to make it generic enough so that anyone in the world could get the drift on beginners' basics and whatever kind of fossils they are hunting.
  5. 22 likes
    Nacre consists of rounded or polygonal (normally hexagonal) tablets of aragonite, which is a form of calcium carbonate. The plate-like tablets are arranged in broadly continuous, regular, mutually parallel laminae which are separated by sheets of organic matrix. That matrix is composed of biopolymers such as chitin, lustrin and silk-like proteins. It’s that unique arrangement, coupled with the fact that the thickness of the aragonite tablets approximates to the wavelength of visible light, which creates the interference pattern of iridescence we call “mother of pearl”. The other parts of mollusc shells are composed principally of aragonite, with some calcite. Although they’re both calcium carbonates, aragonite is geochemically unstable over long periods of time and readily converts to stable calcite in most shelly fossils by recrystallization during diagenesis and post-diagenetic alteration. Those processes also destroy the organic components of the nacre. Although it’s possible for the tablet arrangement of the original nacreous structure to be preserved (it’s sometimes replaced as a pseudomorph by the phosphate mineral apatite), the iridescence doesn’t survive in those circumstances. Intact original nacreous structures with iridescence are only seen in two sets of circumstances. Young fossils, or those where something has prevented the recrystallization… and that “something” is most usually petroleum or one of its derivatives. Famously, for example, the Buckhorn Lagerstätte of Oklahoma is rich in aragonitic shelly fossils preserved with their original iridescent nacre. In fact it’s the oldest deposit in the world which contains such material. It’s a late Middle Pennsylvanian palaeo-seafloor oil seep deposit which became impregnated with asphalt before the sediments lithified and that prevented the nacre from recrystallizing.
  6. 20 likes
    Updated 11/7/17 Although a lot of this has already been posted on a number of topics, I thought consolidation it might prove useful with some additional information. If you're planning to purchase theropod teeth from Morocco's Kem Kem Beds or already have some in your collection check this out. Moroccan theropods are poorly understood and not a lot has been published. Very few articulated skeletons have been found and most are partial and without a skull. There is also lots of mis-information, mostly unintentional, from some dealers but especially online auction sites. Unfortunately these are the most misidentified commercially sold dinosaur fossil around. Please post your interest here on the forum before you buy. Background: The Kem Kem Beds also known as the ‘‘Continental Intercalaire’’ or "Continental Red Beds" is composed of three formations: Akrabou, Aoufous and Ifezouane Formation. The latter two are the dinosaur producing sediments with the Ifezouane being the principal one. They are Cenomanian in age. The attached drawing gives a representation how they lay. The distribution of the different groups of fossils in the Ifezouane Formation can been see in the pie chart below. Dinosaurs make up a small percentage of what is collected. So first lets identify what is known to the best of my knowledge. Theropods that have been described across North Africa (focus on large bodied theropods) Theropods that have been described in Kem Kem: (family) Spinosaurus aegyptiacus * (Spinosaurid) *Some paleontologist believe this species is unique to Egypt and Kem Kem material should be identified as Spinosauid indet. Lots of questions exist over Ibrahim (2014) diagnosis which validated this species. Carcharodontosaurus saharicus (Carcharodontosaurid) Deltadromeus agilis (Neovenatorid) Sigilmassasaurus brevicollis (Spinosaurid) Sauroniops pachytholus (Carcharodontosaurid) Theropods that have not been described from the Kem Kem but isolated teeth exist and have been reflected in scientific papers: Dromaeosaurid sp.? Hendrickx suggested these are actually Noasaurid indet. Abelisaurid indet. Theropod teeth that are sold commercially but no scientific evidence yet to link them to the Kem Kem: Abelisaurus sp. (Not described from North Africa) Rugops sp. (Only described from Niger) Bahariasaurus sp. (Only described from Egypt) Elaphrosaurus sp. (From Jurassic of Tanzania) So what is being sold and what are the issues? Spinosaurid Teeth are well understood by both collector and dealers, see photo. Issues are typically associated with restoration and compositing a larger tooth from multiple teeth. Teeth with matrix attached to them are suspect for restoration so be careful. At least two species of Spinosaurids exits and it's currently impossible to determine if they are Spinosaurus or Sigilmassasaurus or Undescribed taxon. Conflicting taxonomic hypotheses have been proposed. Ibrahim at al (2014) suggest that all specimens found belong to Spinosaurus aegyptiacus. Evers et al (2015) regard Spinosaurus maroccanus and Sigiilmassaurus brevicollis as belonging to the same taxon Sigiilmassaurus brevicollis which is also supported by Hendrickx et al (2016). Ever at al (2015) also described additional specimens from a second unnamed Spinosaurid. Bottom line we do not have enough specimens to eliminate ontogenetic or sexual dimorphism differences and accurately describe Spinosaurids in the Kem Kem. So these teeth are best identified as: Spinosaurid indet. Carcharodontosaurid Teeth, those that are compressed and blade like, first photo. Wrinkles by the distal carina are diagnostic to this species. Mesial teeth are fat, slender and look very different (D shaped) (next three photos). Two species currently are described Carcharodontosaurus saharicus and Sauroniops pachytholus and its impossible to differentiate teeth between these taxons. Similiar to the Spinosaurid debate one exists with these two species and if Sauroniops is valid. Similiar to Spinosaurids the big issue is having enough specimens to make a proper determination in what exists.. For these reasons best identified as : Carcharodontosaurid indet. Theropod indet. There are also intermediate size teeth (1 1/2") that are being sold as Deltadromeus or another theropod. I believe these could be Deltadromeus teeth but until we see scientific evidence this morphology of tooth should be identified as Theropod indet. No skull was found with the holotype or in any other discoveries so we do not know what look like. Carcharodontosaurid serrations Theropod indet. Dromaeosaurid: Teeth being sold as Dromaeosaurus are most likely misidentified, so here is what to look for. There are a few morphologies floating around but nothing as been formally described. Teeth are typically small around 1/2" (1.2cm) to over 1" (2.5cm) One morphology of these teeth are suggested by Hendrickx to be from a Noasaurid dinosaur. Although you see many sellers using the word Raptor next to what they are offering it's unknown if there is a true raptor in the Kem Kem. Abelisaurids are not raptors This figure identifies a study of isolated teeth by Richter (2015) and identifies two morphologies (A to D) and (E to G) as Dromaeosaurid. Mesial and distal carinae show a distinct density difference in serrations. The tip of the tooth extends past the base. On morph E/F a faint but visible constriction between crown and root is visible. The later form suggested by some paleontologists is most similiar to troodontids. Morph variant 3 that I have in my collection but not seen in any papers Mesial and distal carinae range show a distinct difference. A distinct twist to the mesial carina. Abelisaurid indet. With new discoveries we can put a real species name to these teeth but currently they are indet. These are easily identifiable but can easily be misidentified with certain morphologies of Dromaeosaurid teeth. The teeth are very compressed, the cross-section is oval at the base, the mesial side is strongly curved and the distal side is almost straight to the base of the tooth, see red lines in the photo. Mesial and distal carinae range from only a slight to a distinct difference. The only morphological feature that discriminates a tooth of a dromaeosaurid from that of an abelisaurid is the unique mesial and distal curvature profile of the abelisaurid crown. These teeth could belong to Rugops since it's an Abelisaurid but we have no scientific information to support that claim. Premaxillary Bottom Line: There are NO theropod teeth in the Kem Kem Beds that you can currently definitively assign to a Genus to, no less a Species.
  7. 20 likes
    We all would like a Free Lunch or a FREE accessory or FREE samples. What is difficult in identifying fossils found for Free identification on the Fossil Forum presents a bit of a problem. A general lack of important information and associations: 1- LOCATION needs to be more specific. Not the GPS location to keep your location private, but a general area. Utah as a location is too general. Western Utah, better. Millard County, Utah gets it within 800 square miles. 2- GEOLOGY narrows down the possibilities. Cambrian to Pleistocene. You think you found a trilobite in the Cretaceous of Western Kansas. Impossible, as trilobites were extinct after the Permian. By knowing the geological age can be an easy bit of information to start. A Triassic trilobite WOULD be a find for the record books and it would be named after yourself! 3- FORMATION is even more information to narrow down the possibilities. Same as #2. 4- ASSEMBLAGE of fossils also found at this location. This would narrow down the biology. Ocean, brackish water, fresh water, terrestrial, pond, lake... etc. 5- DISCOVERY of specimen. Was it loose? Was it in a gravel bed. Was it washing out of limestone, shale, chalk...etc? Are there others like this specimen? Are they all fragmentary (shallow water and wave action would break up specimens prior to preservation). 6- CHARACTERISTICS that make you think it is a... whatever. Does the specimen have pores in a broken section resembling bone? Appear like a shell of a smooth clam or mollusk, coarse ribbed brachiopod shell, segmented like a cephalopod, nautiloid, crinoid stem section... experience will help over time! Details are important. Size is important. Be observant and then describe. Why did you pick this specimen up? Was it unique or out of place? ******* My experience in a steep learning curve. We ALL share these! ******* #1 Dr. Mark Jewett of the Kansas Geological Survey gave me my first lesson my thinking something was... which it was NOT. I found a complete fossil turtle shell in the Pennsylvanian of Kansas City, Missouri. Not far from the Chiefs Football Stadium while it was being built south of I-70. I sent a letter to Dr. Jewett and where I had found it. Not a turtle. Why? Because of the location and the rock formation being Pennsylvanian... NO turtles existed. It was a flattened Septarian Concretion. A cracked mud ball with calcite filings looking like a turtle shell. My description was accurate. The geological age I gave was correct. It was my interpretation that was wrong. I learned something that day! I hope this helps you as well. #2 I was collecting fossil reptile, shark teeth and fish bone in western Kansas. I found a slab of Cretaceous, Niobrara Formation chalk with a "trilobite". It was segmented and had a front and a back end. It was about 5/8 inch long and 1/4 inch wide. Light colored shell. The front nor back could be distinguished as either end looked the same. Because it was bound in the Cretaceous...it could not be a trilobite as they were already extinct. It was equivalent to what would be a common barnacle (chiton is probably closer to the identification). I was 16 years old on the "turtle and trilobite" find. I cannot recall what the identification of the Cretaceous find was as it was so long ago... but by providing the geology, location and my sketch of the fossil at hand... it was identified by a paleontologist that knew immediately. #3 I was visiting with my family some friends at Fort Riley, Kansas at the age of 15. There is in an area of Permian limestones on the Army base. We adventurous ones went exploring in a rugged rocky area that was heavily wooded. While climbing around looking for fossils I found a footprint impression. The "footprint" was into a layer that was a slightly different layer on the massive limestone wall. If you can imagine a "chicken foot" pressed deeply into this Marly Limey layer was a well made impression and about 3 inches long and the depth of your small "pinky" finger. The three toes up front and one in the back... I took a larger rock and broke this section off and took it home. To this day I wish I had checked on this find further. From what I recall from that impression it is clear to me, 49 years later... this WAS a footprint. Somehow I sold it or traded it right away and never could go any further in knowing if this WAS or WAS NOT. This I regret not following through, but at 15 years old... and a detail orientated teenager when it came to fossils... I still wonder. This could have been a remarkable find... a real possibility. PLEASE TAKE A GOOD PHOTOGRAPH(s), offer as much information as possible and hang on to it until you are comfortable that the mystery specimen is actually something unknown! Science progresses in small steps and some of these steps are MISSING. You could have found that missing step by accident. Offer your find up to fellow Forum members. It might be a routine specimen or not...
  8. 20 likes
    There are a lot of experienced dinosaur collectors out there but for the newbie I thought a topic on the anatomy of bones and teeth would be beneficial, in plain english. Avoids reading pdf's that are difficult to get through the technical terms. Orientation Skeleton The specific sketal structure of a dinosaur varies between theropod and herbivore but the major elements are typical. Skulls of dinosaurs are not comprised of a single bone but many elements The holes in the skull are identified as follows Theropod Teeth Theropod teeth are widely collected let's look at their anatomy and nomenclature Tooth Orientation Apical- The direction from the cervix to the apex (Fig. 1C, E). Basal- The direction from the apex to the cervix (Fig. 1C, E). Mesial- The direction towards the jaw midline, center (Fig. 1C). Mesial can refer also to the surface facing the jaw midline, center. Distal- This term is used slightly differently for teeth versus denticles. For teeth, distal refers to the direction away from the jaw center and towards the posterior end of the jaw (Fig. 1C). For denticles, distal refers to the direction away from the crown, from the denticle base to the denticle apex (Fig. 1E). Proximal- From the denticle apex to the base, proximal refers to the direction towards the crown ( Fig. 1E). Labial- The surface or direction pointing from the skull outwards, thus towards the lips or cheeks ( Fig. 1D). Lingual- The surface and direction towards the skull midline, thus facing the tongue ( Fig. 1D). Tooth Situation and Position Isolated Tooth- Tooth shed or non-articulated with the toothbearing bone. This is what collectors typically purchase. Shed Tooth- Tooth lost while alive,, either falling out due to the eruption of the replacement tooth or when processing food (e.g., biting, impaling, shearing, chewing), and therefore only preserving the crown and the basal-most part of the root. In Situ Tooth-Tooth within the alveolus of the tooth-bearing bone. Erupted Tooth- Tooth that grew outside the tooth-bearing bone, thus fully visible in the mouth. Unerupted Tooth- Tooth within the alveolus and still inside the jaw, and therefore not visible or only partially visible in the mouth. Premaxillary Tooth - Tooth in front of the upper jaw, typically four would exist in a theropod Maxillary Tooth - Tooth in the upper jaw that follow the Premaxillary teeth. Dentary Tooth- Tooth in the lower jaw Tooth Anatomy Crown (co) Portion of the tooth covered with enamel, typically situated above the gum and protruding into the mouth Root (ro) Portion of the tooth beneath the gum and embedded in an alveolus or an open alveolar groove
  9. 19 likes
    Hey guys, I figured this would help out quite a few people here. I've written a guide for taking useful notes in the field. Please read and consider these suggestions! http://coastalpaleo.blogspot.com/2015/10/paleontological-research-tips-i-field.html Bobby
  10. 19 likes
    I decided to do a little experiment yesterday after reading a little about photogrammetry and how it's being used in archaeology for 3D scanning sites. The idea of digitizing fossils in 3D is very, very cool to me. I decided to do a little more research on it and possibly give it a try. For this experiment: All software was completely free. I didn't use an expensive camera....In fact, I used my smartphone to take all the photos. Image size was only 1000x1000px and quality wasn't that great (it's a phone) I didn't have a good light setup. I used the flash on my phone. I had no experience with any of this prior to this experiment. For the subject, I used a whale vert that has some odd preservation. It seems like it was crushed a little during fossilization. The whole thing is off center and cracked in a lot of places. I thought it would be a good fossil to play around with for this. So, I took 46 photos at different angles all around the fossil, making sure to keep the distance the same and tried my best to keep my phone's camera in focus. There were two main steps after the photos were taken. 1. Create a point cloud that could be put into a program and used to make a 3D model from the 46 2D photographs 2. Use the same 46 images to create a texture to apply to the new 3D model. Thankfully, both steps were much easier than I expected them to be thanks to some software created as research projects by different students in a few different universities. I'm happy with the results considering it was done with free software and a cell phone. I could have used higher resolution photos and it probably would have looked nicer, but I didn't for this first test. I plan on messing around with this sort of thing more. There's tons of filters and options in the different programs that I haven't tested to see what they would do...and I haven't even tried a real camera with better lighting yet. I'm guessing that a good camera in direct sunlight would make a huge difference. A couple of things on the model didn't come out right, but that was probably just because I didn't get enough photos from different angles in certain places. Also, the bottom of the vert where it was sitting on the table obviously didn't get photographed, so it's just black. I'm sure you could flip the thing over, do the whole thing again and then put it all together, but that would require a lot more experience with these programs. If anybody is interested in playing around with this themselves, I can post the programs used..or I could write out a tutorial. When some even better software comes out, I can see this becoming a pretty common thing. Imagine a "gallery" full of 3D fossil scans! Whale Vertebra 4½" Tall Miocene Hawthorn Fm. Alachua County, FL Here's an additional two-part scan done using this method and a DSLR camera with more photographs: Titanis walleri Phalanx Pleistocene Gilchrist County, FL Beginner Tutorial The Programs & Configuration First, you need Visual SFM. (This is the program that turns the photos into a 3D point cloud) Next, you need CMVS for Windows or if you're not on Windows, go here. (This is just a few files that we put into Visual SFM that helps create our texture that gets applied to the 3D model) The last thing you'll need is Meshlab. (This is a very powerful 3D program that does all kinds of stuff. We'll be using it to turn our 3D point cloud into an actual model and apply our material to it...among a couple other things) Download Visual SFM & CMVS then extract them. Navigate to the correct folder for your computer and copy the contents of the CMVS folder. I'm on Windows 7 64 bit, so I went to the first folder I extracted, "CMVS-PMVS-master" > CMVS-PMVS-master > binariesWin-Linux > Win64-VS2010 and copied everything in there (minus the Readme.txt). Paste those files directly into the Visual SFM folder (the one with all the .dll files where the application to launch the program is) that you just extracted. Obviously, this is a one time thing. You get those files in the right place and every time you open Visual FSM to make a 3D model, it'll have CMVS right where it needs to be. Photographing When I took my photos, I placed the vert on a piece of newspaper with a lot of different colors, lines, images, etc. It's important that the software has common places of reference between different images so it can map out he point cloud accurately. Here's my vert set up ready to be photographed: Thinking about it now, it probably would have been smarter to elevate the vert slightly above the newspaper on a little block or something. I had a little trouble cropping the bright newspaper away from the vert. I took photos starting at a low angle spaced out as I slowly rotated around the fossil. I'd take a pic, move a tiny bit, take another, move a tiny bit, etc. Here's what four of my photos in sequence look like: I went in a full circle until I was sure that I had rotated around the fossil completely and even overlapped a bit, taking photos of the same angle I started with (better to have too many than too few). Then I angled the camera (well, phone in this case) at about a 45 degree angle and rotated around the fossil completely again. Those photos look like this: As you can tell, this are not great photos. I think that the model would have turned out much better looking if I took better photos in better lighting. After I completed that pass, I took one photo of the very top of the vert, facing downward. I made sure to always get a fair amount of the newspaper for tracking purposes. Then I used a great free program called Photoscape and it's batch editor to apply the same filter and crop to all the images at once. Make sure not to crop out your newspaper or whatever you're using to help with tracking. Do not use images with larger dimensions than 3200px! I read in a couple places that this would cause worse tracking and a lot of other problems. If you want to experiment with larger than that, go for it and see what happens..When I tried it, the program ran for a very long time and eventually froze my computer...but my original images were over 5000px each. Visual SFM When your photos are done, open up Visual SFM by going to the folder you extracted and clicking on the application. This is what it looks like: I wrote out some arrows to the things you'll be using in there. #1 is Open Multiple Images. Just click that, navigate to your images and upload them. You'll see the log window to the right doing some stuff....You should see your image thumbnails in the program in just a few moments. When that's done and there's no more activity in the log window, click on #2, Compute Missing Matches. This is the first thing that some computers could have trouble with. This one can take a little while depending on how many images you have and how large they are. When this is done and there's no more activity in the log window, we can get to the cool stuff. Click on #3, Compute 3D Reconstruction. This part is seriously amazing. It takes all of your images and automatically calculates where you were in relation to the object when you took the photo. Then it shows all the places an image was taken and it displays the point cloud in the center. It looks like this: The squares are everywhere I took a photo...You can see that I did a circle around the fossil down low and then a very sloppy "circle" above it. In the center, you'll see your sparse point cloud. If you want to make the little image icons bigger or smaller, it's ctrl + mouse wheel, if you want to change the size of the point cloud points, it's ctrl + alt. Time for the next step. When you clicked on button #3 and got your point cloud, a couple new buttons showed up. This is the one you need: #4 is Run Dense Reconstruction. When you click this, it's going to act like you're saving something. What you're doing is giving the software a directory to dump the files it's going to create. Make a new folder, give the file some name and click save. When you click save, look at the log window (if it's gone, the show/hide button for it is at the top, far left) and look for this: If you see the highlighted part, it means you correctly moved over the files from the CMVS folder you downloaded into the Visual SFM folder. It'll tell you that "this could take quite some time" and it definitely does. For my project (46 images at about 1.2MB each - 1000x1000px) it took 5 - 10 minutes, but before I resized those photos they were over 5000px each and this step ran for nearly an hour before my computer finally froze. Like I mentioned above in the photography part, I read in a few places that your images should be below 3200px on the longest side. You might want to think about closing down other programs that use up a lot of memory while you run this unless your computer has a lot of memory to spare. I closed out my browser and a bunch of other stuff just in case. When the log window says this is done, you should be able to hit Tab on your keyboard and see your dense point cloud....again, you can mess with the size of the points with ctrl + mouse wheel. This is still just a point cloud even though you'll start to see some color and image coming through. There's no need to save anything after this step is done. The program automatically wrote everything you need into the new folder that you created. And that's it for Visual SFM! Meshlab Go ahead and install Meshlab if you haven't already. It can look a little overwhelming at first, but we'll only be doing a couple pretty basic things. This is what Meshlab looks like: Go up to File and click Open Project (or the second button from the left, #1 in the photo above). Remember the folder you had to create when doing the last step (the dense point cloud) in Visual SFM? Navigate to that folder and you'll see a .nvm folder with the name. Open that file. It'll take a few moments to open. When it does, you'll see your point cloud open up into the program (upside down). Now is a good time to try to learn how to navigate around the viewport. The mouse wheel zooms in and out. Holding the left mouse button and moving the mouse rotates around the center. Holding the mouse scroll wheel and moving the mouse will pan the point cloud (or later, the mesh) around. I usually center it in the middle of the center rotation widget. Holding Alt and scrolling the mouse wheel will change the size of your point cloud points....You may need to do that to make them easier to see since we need to delete some soon. All this might take a little getting used to, but if you're patient you'll get the hang of it. Next, click on Show Layer Dialog, the #2 button in the image above. You'll see the little window on the right pop up. If you're at all familiar with photo editing, this layer window should be pretty familiar to you. Now we need to get our cameras showing up. Go to Render (#3) > Show Camera (#4). From there, go over to drop down arrow next to Show Camera on your side window below your layers (#5) and click it. Check on the Scale Factor here and make sure it's set to something like 0.04 or smaller depending on what you want. When I first did this, the camera scale factor was very high when I first clicked on Show Camera and it made it so I couldn't see my point cloud anymore. Time for bringing in our dense point cloud. First, click the little eye next to your layer in the side bar (#6) and you'll see your point cloud disappear. Next, go to File > Import Mesh (#7) and navigate to the same folder you created in Visual SFM where your .nvm file was. You'll see in the same folder a .ply file with the same name. Click that and import it. Reposition the mesh in the center and zoom in. Under Show Camera on the side bar, you may want to uncheck Show Raster Cameras so they don't get in your way for this next step. We're going to be selecting and deleting the stuff that we don't want in our finished model. Position your model carefully and click the Select Vertexes (#8) button. You can then click with the mouse and drag a rectangular selection around the stuff you don't want (#9). Be careful NOT to delete any of the actual model, only the surrounding stuff that was used for tracking (the newspaper in my case) and any random artifacts that might be hovering above or around the model. This isn't difficult, but it can be a little time consuming. This is why I recommended above that you elevate your fossil on a little block or something. Then you could just change to a side view and delete all the newspaper at once, cutting the block in half. When you drag the box around the stuff you don't want, that stuff will turn red meaning it's selected (see #9). When you have the right stuff selected, click #10, which is a Delete Vertices button. The area selected is gone now. Repeat 8, 9 and 10 changing angles carefully to get rid of everything that you need gone. Sometimes the wrong layer gets automatically selected (the invisible one) and when you hit the delete button, it won't do anything. Just click the layer ending in .0.ply if the top one gets selected and keep going. Don't hit the delete button if even a tiny piece of the model is selected...There's no undo button that I've seen, so if you make that mistake, you may have to go back to step 7 and import the mesh again. Here's another angle I used: Remember that you can hold Alt and scroll the mouse wheel to make the points bigger and smaller. If they're too small, you'll have trouble seeing what to delete and what not to. Next, go to Filters > Point Set > Surface Reconstruction: Poisson (#11) here: Then change the settings in the box that pops up to 12, 7, 1, 1 (or experiment a little, but that's what I used) like this: When that's done, hit apply and let it run. What comes out is a 3D model of your fossil! It's just missing the texture right now, but it's still very cool looking. Click the little eye on the layer that ends with .0.ply to hide it. It'll look something like this: Next, we need to go to go to Filters > Selection > Select Non Manifold Edges (#12), making sure the right layer is selected like so: A box will pop up. Just hit apply, then click the Delete Vertices (#13) button. This is just a preventative measure, you shouldn't notice much happening when you click delete. We're getting close! Just one last step and you'll have a fully textured 3D model. Go to Filters > Texture > Parameterization + texturing from registered rasters (#14). A box will pop up. I doubled the size of the texture and left everything else default. The default is 1024, I changed that to 2048. Go ahead and name your texture whatever you want. This step is taking all those images we took and making a single image file that has all angles on it. Hit apply. And there you go! A fully textured 3D model of a fossil from nothing but images: You can go ahead and export your model now. Click File > Export Mesh, give it a name, select the file type drop down here: I made sure to save in a couple different file formats. I saved in .obj and .dae. When you go to upload the 3D model somewhere, all you have to do is upload one of these files and then find your texture image that you created on step (#14) to apply to it. Keep in mind that this technique is not limited to small objects. You can map out environments in 3D too. Archaeologists use this technique (usually with high tech equipment) to take 3D models of archaeological dig sites. This technique can also be used for very detailed topographic mapping if you had a way of taking aerial pics. I'd love to see if anybody gives this thing a shot. If you try it and have trouble, let me know...I'm still very much a newbie at all this, but I'll do whatever I can to help figure it out. I'll post more in this thread as I make more 3D fossils. If anybody gives this a shot, have fun! It's definitely a learning experience. -Cris
  11. 17 likes
    First up, the seller of this egg stated upfront this is a replica, so this isn't a scam warning. Here, we have an oviraptor egg that could fool even experienced collectors. It looks realistic because it's made out of real oviraptor eggshells. It's even covered with a coating of matrix. This is common practice; I've seen hadrosaur eggs are faked this way, with plaster mixed in to make the egg seem round and heavy. For reference, here's a real Oviraptor (Elongatoolithus sp.) that's been professionally prepped. Oviraptor eggs are commonly faked, so four ways to get a real one is: 1) Get a prepped one, preferably with matrix removed. The eggshell should be black 2) Avoid eggs that are perfect. Real eggs have cracks, and sometimes missing entire chunks of shells. 3) Get one without a matrix base. This isn't a sure-fire method, but I've noticed many fake oviraptor eggs have matrix bases, whereas I can't say the same of those free of matrix. Perhaps the fake eggs require a matrix base for support during their construction process. 4) Price. Again, this is arguable, but the real Oviraptor eggs I've seen often comes with price tag several times that of dubious ones. Having sent some eggs for prepping in the past, this is justified because the cost and time of prepping may cost more than the actual egg. Some scammers like to lure people in with bargain prices. Chinese eggs flood the market, and for many collectors, a dinosaur egg is a must-have. There are more fakes than there are real ones, so take extra care if you seek to buy one. As always, if you're unsure, post pictures here and we will try to help.
  12. 17 likes
    A few years ago most of the smaller theropod teeth from the Hell Creek/Lance Formations were identified based on teeth from the Campanian assemblages of North America. Over the past couple of years new discoveries have shed new light on the theropods of the end of the cretaceous and new species have been described. I have addressed these on separate topics but decided to put all of these together to get a better view of the current picture of the upper Hell Creek and Lance formations. If you see any omissions or errors feel free to let me know. Tyrannosaurs: There are two Tyrannosaurs described Tyrannosaurus rex and Nanotyrannus lancensis Teeth of these two tyrannosaurus can be distinguished between one another however there may be some positional teeth that can be difficult and mimic one another. Denticles on both on both anterior and posterior carinae can be identical in size and shape however the carinae on Rex teeth are more robust. Serration count from my examination is not important on smaller teeth. Nanotyrannus teeth typically do not exceed 2 1/2". The best way to distinguish these teeth is to look at how compressed they are and the cross section at the base of the tooth. Rex dentary teeth are oval at the base and maxillary teeth are a bit more compressed. Some maxillary teeth can appear to look like Nano so other features need to be examined like the robustness of the tip and carinae. Nanotyrannus teeth are unique as tyrannosaurd go, they are very compressed across the entire crown and their cross section at the base is rectangular. Basically Rex teeth are fat and Nano are flat. Here are examples of the cross sections at the base of a couple of Rex teeth under 1 1/2" and adult Nano's Rex (teeth are oval but can vary depending on position.) (Maxillary teeth are more rectangular) This figure represents tyrannosaurid teeth from the Judith River but is applicable to T-rex and shows the cross sectional shape at the base for different positions. Morphometry of the teeth of western North American tyrannosaurids and its applicability to quantitative classification Article (PDF Available) in Acta Palaeontologica Polonica 50(4):757–776 · April 2005  Nano (teeth are rectangular) Maxillary T Rex teeth can also take this shape so one needs to consider other features. Looking at compression Rex teeth are fat with robust tips Nano teeth are flatish Aubysodon molnari is a tooth taxon known from unserrated Pre-maxillary teeth. This taxon is a "nomen dubium" dinosaur and premaxillary teeth being sold belong to one of the other two Tyrannosaurs in these assemblages. They should be labeled as "Tyrannosaurid indet" because its impossible to differentiate between species. Albertosaurus sp.is not present in these assemblages Dromaeosaurids: There are only two described Acheroraptor temertyorum and Dakotaraptor steini and Zapsalis sp. is also present. Saurornitholestes and Dromaeosaurs species are not present. Acheroraptor temertyorum Identification: Like all Dromaeosaurid teeth the denticles are key and different between those on the anterior and posterior carinae. You should easily be able to see that the posterior ones are much larger. If the denticles are identical its probably a juvenile Nanotyrannus tooth. Secondly there are apicobasal ridges on the crown which are diagnostic to this species. There can be several on either side and fewer on posterior located teeth. The teeth are recurved and typically under 1/2" (13mm) long. Dakotaraptor steini Identification: Like all Dromaeosaurid teeth the denticles are key and different between those on the anterior and posterior carinae. You should easily be able to see that the posterior ones are much larger. If the denticles are identical its probably a juvenile Nanotyrannus tooth. These teeth are larger than Acheroraptor and lack the ridges seen on the crown. The teeth are recurved and compressed and larger around 7/8" (2-2.3 cm) in the holotype. However dont dismiss smaller teeth, juvenile teeth are around. The holotype serration count per 5mm is (Distal 16-19) and Mesial (19-27) I have yet to find any of these teeth and believe they are not common. Nano teeth can mimic these its all about serrations difference. Zapsalis sp. Identification: Similar to Z. abradens from the Judith River Formation. Very compresses tooth with rounded serrations on the distal side and a smooth mesial edge. One flat tooth surface with longitudinal ridges. Troodontids: There are at least two present Stenonychosaurus sp. and Pectinodon bakkeri. but only one described Pectinodon bakkeri. Stenonychosaurus sp. is an easily recognizable tooth. Denticles strongly hooked and turned toward the tip Pectinodon bakkeri signicantly smaller 6mm or less than Stenonychosaurus teeth. Comb like denticles on posterior carina, lacking on the anterior side.. Positionally these teeth have different morphologies can been see in the photo. Reference from : Vertebrate Microfossil Assemblages by Sankey and Baszio Other Teeth: Paronychodon lacustris type teeth are flat on one side and usually bear three or more longitudinal ridges. The other side is convex and can be smooth or longitudinal ridges can be present as well. Richardoestesia gilmorei. these teeth are quite varied in shape and size and are also common. Some are straight and others are slightly recurved. Denticles are often limited to the posterior carina and individual denticles are minute. If the denticles are present on both carinae they are identical in size. The serrations should look like these (scale .2mm) Richardoestesia isoceles. Typically are very compressed, elongated and form an isosceles triangle. Fine serrations can be present This species along with the Paronychodon is currently under study and will most likely be described to a new taxon which may not be dinosaurian . Albertonykus sp. is known from bones. Its teeth are very small and pointed. Photo of tooth is from the smaller Mongolian species Mononychus olecranus Morph types isolated small theropod teeth are abundant in these assemblages. Morph types exist and determining the taxonomic affinities of these teeth is problematic. So be prepared to identify these teeth as Theropod indet. Note A lot of what I've described here requires a detailed examination of the serrations. The crisper they are on your tooth the better the opportunity you will have to identify them. having some magnification capability helps Bird: Avisaurus archibaldi This tooth is typically sold and known as A. archibaldi. Unfortunately the holotype is known only from one bone a diagnostic tarsometatarsus and NO other skeletal material has been published. So we really do not know if this morphology of tooth belong to this enantiornithine bird. Its probably best ID as Avisaurid indet.
  13. 17 likes
    It's September and a great time to go out in the badlands of Montana and South Dakota hunting for Dinosaurs. I try to go out at least twice a year unfortunately family health issues prevented me from a earlier trip so I was happy to be able to go on this one. My South Dakota site is in the upper Hell Creek Formation and full of the hadrosaur Edmontosaurus annectens plus the occasional theropod tooth. All of the bones collected come from this site however some of the teeth I show come from a channel deposit in Montana. I've been collecting this site for 20 years and its still delivering. We are on the edge of a bluff and the fossil layer can be between 2 to 4 feet. Lots of good bones are to be found but we also have lots of punky or junk bones and about 70 % is collectible. The site is quite large and like I said last year we have no idea of its size but it contains scores of hadrosaurs all disarticulated. No skulls are found but all the elements that make up a skull are collected. Some pictures of the site and locality The collecting area is between the white lines My tools are pretty simple and those shown are used 90% of the time. I also use a pick. We have no equipment to remove the overburden so its our biggest challenge and can be quite daunting for those not physically in shape, like most of us The collecting layer starts off with a crumbly pebble deposit where the teeth are found then turns into sand where little is found and most of the bones are in the lower hard clay deposit. Most of the bones fracture when exposed to air so glue may be necessary to keep them together during extraction. I use two Paleobond products : PB4417 which is a field consolidant and comes off easily during prep but does not have structural strength. PB002 is used when I need strength on larger bones. I also carry a debonder just in case I glue my fingers together or as in this trip a fellow collector glued his glove to his hand. Glue can be dangerous since it cures quickly. Its more a safety issue but sometimes needed on bones/teeth in the field. I found this product "Golden West Super Solvent" used in the prep lab of the Royal Tyrrell Museum. Its effective has acetone but had no odor or effects on the skin and is not flammable or volatile. Its more costly than acetone but for the amount I use it works and no smell. In addition to showing everyone what I found I would also like to share the process of extracting some of the bones. Very few get to collect in this formation so it might be interesting to see the process and how hard it is to get from the Dirt to the Finished product.
  14. 17 likes
    Hello all, as some of us may have noticed while skulking Ebay, there has been a trend with many "specimens" of certain Chinese vertebrates being listed and sold: Turtles(Manchurochelys), Birds(Confuciusornis) and even Reptiles(Monjorosuchus). Firstly, most of us here will agree that all of these specimens are faked! Since there was a recent thread asking about the authenticity about the turtles, it is clear that many amateur collectors(myself included) are considering buying or have bought some of these "fossils" and I hope my observations in this post can help prevent you from being scammed. Last year, before Ebay was flooded, I acquired two specimens(a turtle and reptile) against my better judgement from a different Japanese auction site. One of the pieces arrived broken cleanly in two, and I was able to tell that the reptile and the turtle(by association with the same dealer) are faked. To the untrained/unfamiliar eye however, it becomes hard to distinguish as these fakes are crafted with a level of detail rarely seen before. These are not churned out from an assembly-line, but rather painstakingly hand-crafted so that every piece is more or less unique. They are usually painted grey or in some cases a shade of brown like mine. Some of these specimens are even fabricated on the same Jurassic/Cretaceous matrix with remains of real Lycoptera fish. Also, as you can see from the following photos of the broken areas, the reptile in question is sculpted from some kind of epoxy material. One of the limb bones even fell off cleanly! The details of this specimen has some resemblance to real examples of Monjorosuchus(Manchurosuchus). Not everyone will be able to tell the difference! Thanks to the advice of Scott(Piranha) on TFF, I stopped myself from acquiring a "Confuciusornis" as well and was able to claim back my money from postal insurance. I will say with 100% certainty that all these vertebrate fossils are crafted by the same process as the "Monjorosuchus" above. Edit: Here are a couple more pictures of the faked Confuciusornis, the skull looks completely iffy but everything else is very intricately crafted! More pictures of the bird here. A few last observations, I noticed that these listings on Ebay started popping up last year. At first, it was just a few turtles, but have now expanded to this so-called "Trinity" of vertebrates. It is clear that there is big money being made from this and amateur collectors need to know what is going on. There are multiple sellers taking advantage of this new cash cow(or belonging to the same syndicate) who build up their Ebay rating by selling small cheap electronics/hardware before listing these fakes in an attempt to fool you. Also bear in mind these are all private listings and it is not possible to tell if they are shill bidding on each other's items to drive prices up. Ebay used to have people moderating their fossils section for fakes, but this is not the case anymore and I doubt reporting these listings will have much impact. I urge you all to consult TFF members for advice before making any purchase if you are uncertain! I have included more photos at higher resolution at the following imgur album(warning:large size): http://imgur.com/a/076uT. I hope that any prospective buyers out there will learn from my experience. Also, if there is anyone here with more experience with these kinds of vertebrates, please share your thoughts!
  15. 17 likes
    Yes, it makes perfect sense Bob. It’s another of those “difficult to answer” questions, but I’ll have a go. The enamel “layer” of shark teeth should more properly be termed “enameloid” from a histological point of view. It actually consists of four zones: a juxta-laminar zone containing newly polymerized mineralizing fibrils (tubules); a pre-enamel zone assembled from matrix constituents; palisadal zones of mineralizing fibrils (tubules); and interpalisadal zones containing granular amorphous matrix, fine unit fibrils, and giant cross-banded fibres. Considering the layer as a collective, you could see it as mostly composed of hydroxyapatite (a form of calcium phosphate) crystals formed by secretion and nucleation onto a preformed protein matrix that consists of several hundred different proteins, of which collagens represent the largest group. The matrix accumulates on an emerging tooth at the tip and then extends over the whole crown. Soon after the matrix appears, it begins to calcify by deposition of hydroxyapatite crystallites. The proteins are easily degraded and are the first to disappear after death. Fragmented amino acid derivatives and polymerised byproducts from them might survive the fossilization process (very rarely) but not the proteins themselves. So, you could say that since the proteins have gone, then you no longer have “enamel” in the fossil. The zones will be lost at different rates (assuming they preserved in the first place) and which zone is exposed will largely determine the extent to which the surface looks "enamel-like", together with colouration effects from mineral-staining. As for the hydroxyapatite, during the early stages of fossilization, it is sometimes the case that new crystalline material grows from the original hydroxyapatite. These secondary crystals are very much larger than those that would have originally been present, but much fewer in number. They’re probably the result of the original hydroxyapatite being re-solubilized under pressure and being re-deposited in the spaces left by the decayed proteins. Typically, what you can see under the microscope is a more pronounced crystallinity than was present in the original tooth and a mixture of crystal sizes that could loosely be divided into “tiny” and “large”. Interestingly, the “in-vivo” alignment of the crystals (the long axis) often persists in the fossil. A major proportion of the hydroxyapatite is probably original material in many fossils but it’s arguable whether it should be termed “enamel” (probably not). One other interesting note is that hydroxyapatite in fossil teeth (and more especially in fossil bones) frequently has elevated levels of fluorine, which substitutes for the hydroxide groups to create fluoroapatite. The crystal size is usually unchanged in those circumstances. Quite why this happens is not well understood, but the levels are well above those that could have originally been present. There is evidence to suggest that this happens very early on in the fossilization process and may be an important step in stabilizing the mineral, such that it determines the subsequent degree of preservation of detail at a micro-level. The oft-quoted “molecule by molecule” replacement to describe the mineralization process for fossilization is 100-year old textbook stuff and a long way from what we know today about how most mineralized fossils are formed. It’s a useful simplification to help people get their minds round what happens, but no more than that.
  16. 16 likes
    To start with, all those names apply to the same species. The different generic names reflect various opinions about the taxonomic relationship of that species to other mega-toothed sharks. Other posters are much better versed in the history of the various names and hopefully they will offer comments. I'll just mention that "Carcharodon megalodon" reflected a belief that megalodon was closely related to the white shark. This idea has been pretty much completely discounted due to the numerous differences between megalodon and white shark teeth; the similarities are mostly superficial, and the generic assignment is no longer regarded as valid. I believe the currently favored combination is Otodus megalodon. Although the frequent shifting of names can be irritating, it helps (maybe a little bit) to remember that Linnean taxonomic groupings above the level of species (so genera, families, orders etc) are artificial constructs, and in a way they are hypotheses about the relationships between species. When someone names a new genus, they are making a statement that the species they are studying is sufficiently different from all other named species that it cannot be grouped with them in the same genus. Of course there is no hard and fast rule for "how different is different enough". Historically that has been a matter of judgement, hopefully by someone with a great deal of familiarity with the set of species under consideration. However it is still fairly subjective, with some researchers defining genera very narrowly and splitting species between many genera (so-called splitters), and those taking a broader view and grouping species that cover a large amount of variation under a single genus (so-called lumpers). These days tools for analyzing large matrices of measurements of morphological features can perhaps make the practice a bit more objective, in that you can reconstruct phylogenetic trees and look for natural clustering of species into higher categories. Anyway, when two species are put into the same genus the scientist is making a hypothesis that the two species have a very close phylogenetic relationship; you might think of them as small twigs from the same small branch of a phylogenetic tree. Species that are put in different genera but, say, the same sub-family are twigs that split off the same branch but further apart. In this way the names come to reflect the evolutionary history of the species. So putting species in the same genus reflects the researchers ideas about the closeness of the relationship between the species, coupled with her ideas about how narrowly or broadly to define genera. This hypothesis is dependent on data (the morphology of the species, which can be reduced to measurements of lots of characters), but that data is also filtered by ideas about the relative importance of individual characters. In the past much weight was given to the presence or absence of serrations on shark teeth, so species might be grouped based largely on that character. Nowadays it is recognized that serrations can be gained or lost quickly in evolutionary time, so they can evolve independently (convergent evolution) multiple times and they may not reflect actual close relationships. Other characters are now given more "weight", in other words they are thought to be less likely to evolve multiple times so their presence in two different species is likely to be due to actual close relationship, such as sharing a common ancestor that had evolved that feature. An example might be pores that represent the pattern of blood vessels in the root. Shifting hypotheses about relationships of "megalodon" to other sharks, based on more data (such as more transitional fossils, or better understanding of how to weight characters in phylogenetic analysis) will inevitably be reflected in changes in the choice of genus name to apply. Don
  17. 16 likes
    Here's a paper explaining how the spiral cracks form: Spiral Cracks in Drying Precipitates Z. Néda, K.-t. Leung, L. Józsa, and M. Ravasz Phys. Rev. Lett. 88, 095502 – Published 12 February 2002 Neda et al 2002 Spiral cracks in drying precipitates.pdf A key figure: Appears to involve two generations of cracking. First generation forms "shards" and then the spiral crack forms along the detachment front as the dried fragment detaches from the substrate. There are lots of other papers on this if you look up spiral cracks and desiccation. You can even do an experiment easily at home to watch their formation!
  18. 15 likes
    I continue to see collectors get scammed on items they are buying on auction and online dealer sites. So I thought it would be good to revisit a few of my favorite ones. Dromaeosaurus species teeth from the Hell Creek or Lance Formation. There are only two Dromaeosaurids described from these formations : Dakotaraptor and Acheroraptor and Dromaeosaurus is not one of them. Dromaeosaurid's have two important characteristics to look for , they are recurved and the Mesial serrations are much finer that the Distal ones. Most teeth being sold are probably juvenile Nanotyrannus like the one I show in the photo that is described as a Dromaeosaurus. Nuthetes theropod teeth from France There is still a question if this is a valid taxon but that is not my issue in this discussion. If valid, Nuthetes is a Dromaeosaurid/Velociraptorinae so it need to exhibit the morphology of one. The ones being sold are triangular in shape and have similiar serration on both edges, like in the photo. A Nuthetes tooth should be recurved with Mesial and Distal serrations very different. Most being sold should be identified Theropod indet. Sarcosuchus teeth from the Kem Kem of Morroco There are over 8 different Croc species described from the Kem Kem and Sarcosuchus is not one of them. It may exist in this fauna but the odds of one being available for sale are low and difficult to differentiate with other species. This is what is typically sold. Pterosaur claws from the Kem Kem of Morroco There listing usually talks about how rare and special these claws are and why you need to purchase it. Well I do not believe there are pterosaur but do not know what they are. The most common description Ive heard is fish gill rakers. If they were claws the proximal end would have an articulation surface and not be flat. I've seen these for sale up to $1,100 USD Kem Kem theropod claws Fabricated claws from this region unfortunately is a common occurrence. One needs to be very diligent when buying these claws and the dealer may not even be aware they are fake. Don't hesitate to bounce concerns off forum members. They are usually expensive and sometimes hard to recognize. Daspletosaurus teeth There are three Tyrannosaurid's from the Judith River and Two Medicine Formations: Gorgosaurus, Albertosaurus and Daspletosaurus. Teeth under 3" are indistinguishable between one another and you should not pay a premium or purchase it because it's being sold as Daspletosaurus. Albertosaurus teeth can get over 3" . Deltadromeus teeth from the Kem Kem of Morroco Although described from the Kem Kem we have yet to understand what these teeth look like since no skull has ever been found. Pure speculation on those being sold as one. Rugops teeth from the Kem Kem of Morroco This is a species that has been described from Niger and not the Kem Kem. Its an Abelisaurid, so teeth being sold as that may be from this animal but until a skull is described it's pure speculation.
  19. 14 likes
    Hi everyone, I've had a couple people lately asking me how I restored the megalodon tooth I posted about a couple years ago here. I decided to pick out a damaged tooth on Ebay for $15, and take you through it step by step. Here we go! What You'll Need: PaleoBond Sculp Hardener and PaleoBond Sculp Resin (You can substitute with epoxy putty but dries faster and is less malleable) X-Acto Knife Wire brush or any brush with very stiff bristles Any brand of acrylic paint from Hobby Lobby or Michaels (specific colors listed further below) A small paintbrush of reasonable quality Fine sandpaper and steel wool SITUATIONAL: Clear gloss used for acrylic paint Step 1: Examine the fossil and the damage. This is the bargain tooth I purchased. It's over 5 inches, and you can see it's actually in nice condition minus the chunk missing. The broken edge is still sharp and jagged, so it appears that the damage occurred recently as opposed to millions of years ago. To fix this tooth I will need to recreate parts of the root, bourlette and enamel. Since the tooth has fairly nice detail I will definitely need my razor blade to create fine lines and serrations. Step 2: Prepare and apply the putty Pull out a small chunk of putty from both the PaleoBond Hardener and Resin containers. Knead them together with your hands until the colors mix completely. Mix thoroughly otherwise the putty will be squishy in some places and will not harden properly. Once mixed, take a very small piece from your ball of putty and mash it into the damaged area of your tooth. Step 3: Building your shape Less is more when you're working with putty. Smaller pieces are much easier to manipulate, so build gradually piece by piece. You may get to a point where you're putty structure is not stable enough to continue building on. Take a break for 2-3 hours to let the putty dry and come back. When building the root of my example tooth, I had to take two or three breaks in order to get a foundation sturdy enough for me to continue building up. Pay attention to how your repair is taking shape and keep the edges of your putty level with the natural edges of the tooth. This is one of the most difficult parts of the repair, but it makes a big difference when you get it right. Wash your hands every once in a while to keep them from getting to tacky and sticking to your putty. Step 4: Begin to work in detail As your repair begins to fill out, work in natural-looking cracks and lines with your X-Acto knife and fingernails. Mimic the natural aspects of your tooth as best as you can. When repairing my tooth's root, I created fissures and cracks that matched up with the real side of the tooth. This really helped create the illusion that the repair is natural. To mimic the heavily detailed surface of the tooth's root, I gently pushed my wire brush into the surface multiple times. Try to do this when your putty is still wet because if the putty is dry it takes much more effort. ALSO, make sure to keep the putty very smooth in areas of enamel (excluding line/crack detail). Once the putty dries, take some fine sandpaper and smooth it out further. Steel wool can then be used to make the surface even smoother. (Thanks to steelhead9 for those two tips!) Be very anal retentive about this. You will appreciate it in the next step. Step 5: Paint! This is my favorite part because it's the point in this process where the repair finally comes to life! It also happens to be the most frustrating part. Depending on your tooth's coloring you will likely need the following colors in your arsenal: Umber Black White Sienna (maybe) Red (maybe) Blue (maybe) This step is where perfectionism (making the putty super smooth in areas of enamel) really pays off. Paint highlights the imperfections of your putty, so don't be disappointed or surprised if you have to start over. I started over probably two or three times. As far as painting technique, I would love to give more instruction, but that is really an entire lesson in itself. Don't be afraid to paint a little onto the actual fossil. You will need to do this in order to properly camouflage the merged area of putty and tooth. In fact, don't be afraid to overlap your putty a millimeter or so onto the tooth as well. My biggest tip though is make sure you paint in a well lit room. Painted colors can look spot-on until you step into good lighting... Step 6: Apply a finish depending on your tooth Some teeth with top-quality enamel will need a glossy finish applied in order for the repair to look natural. My tooth did not require a high-gloss coat. Either way, you ought to apply some kind of light finish to your tooth in order to preserve the repair from scratches and humidity. I have not yet found the perfect finish to do the job, and am still experimenting with spray finish, clear acrylic gloss, clear furniture gloss, low-gloss nail polish, etc. Feel free to add your thoughts and recommendations below! Below you can see my repaired tooth. The root could use a bit more texture and the enamel and bourlette are a little rough in places. Overall, I'm happy with the result though. I hope these instructions were helpful! If anything is unclear or too general I'd be glad to elaborate further. Good luck!!!! Your Fellow Fossil-Fanatic, Lauren
  20. 14 likes
    Hi all. eBay is generally a good website for us to get fossil specimens as long as we do the proper research, and seek out reputable sellers. However, certain fossils pop up every now and then that are obvious fakes, and not every buyer is diligent enough to know so. What we can do is to report these listings. Believe it or not, sometimes they do get taken down. To begin, say you notice a fossil you know is fake. Click on Report Item on the top right, it's above the eBay item number. eBay takes you to another screen: Choose Listing practices > Fraudulent listing activities > You suspect that a listing is fraudulent Hit Continue, and you'll be given an item number. Hit 'Send Report'. You do not need to be a bidder to make this report. You'll know the report is made when you're taken to this new screen: Ultimately, the best practice if you shop on eBay is to do your due research. Ask the experts here; they are more than willing to point out when a fossil is fake. I've personally saved thousands just by helpful advice here. Also, if you notice any fake fossils, do us a favor as well by posting about it here, but do not mention the seller's name or identity; we are here to learn, not conduct a witch hunt. Good luck
  21. 14 likes
    Welcome to the Forum. This looks like fish material - you can clearly see a fish vertebra in your second to last photo. The plates look like the left side of the skull, and possibly more. Neat find. You might be able to scrape away the excess matrix using dental tools. Thanks for posting this - and Welcome, again. Regards,
  22. 14 likes
    Listen and learn, Grasshopper. There is much to know; take the time to know it Please understand that an erroneous comment made here, and left uncontested, will be read by thousands of people, some of whom will take it as true. Best to stick with what you know and have verified, or to ask your thought as a question ("Is it usually difficult to classify any further than "fish" with just that much bone?").
  23. 14 likes
    Figure didn't upload...trying again:
  24. 14 likes
    Compressed Air Tools....Most compressed air tools have quite a high air consumption so its essential you aquire a compressor with a decent capacity storage tank.... Im running a 70 litre compressor at the moment and when im using the die grinders or chisels, it is running continuously to maintain the pressure I need.... With a bigger storage tank, say 150 litres, this would not really be much of a problem....It would have long quiet spells before needing to fire up and refil the tank....also compressors can be noisey, so its important you consider this when thinking of buying one.... there are quiet compressors on the market which cost probably two or three times the amount of conventional compressors.... Air Chisels... These are good for removing upto 3-6 mm of rock at a time... after the inital bulk material has been removed, while you are getting closer to the fossil... a smaller chisel point is more effective for removing greater a thickness as the force from the chisel will then be applied to a smaller cross sectional area... you can see in the photo ive flattened an area of rock adjacent to the stil saw finish, quite quickly in less than a minute using this equipment... eye protection is essential.... Die Grinder.... These fitted with tungsten burrs and grinding tips can quickly smooth off a section of rock, or remove a concave area getting closer to the fossil... they utilise quite a high air consumption, but again are quite effective... In less than a miniute I smoothed over the surface of the flat area I had just created with the air chisel... Eye protection is essential.... Airpens.... I use a Chicargo CP pen for the bulk of my work.... without going into too much detail at this point regarding techniques, and treating it as a mechanism for matrix removal, its very easy to think a cp pen will remove 2-3 mm of rock across a surface .... you use it like you are ploughing a field, applying an even pressure, creating furrows in the rock... the next pass you do at 90 degress to the first, taking the tops off the previous furrows... it can be very effective....The forward exhaust of the air greatly assists visibilty when using this type of pen, blowing the dust and grit away as you progress... Eye protection is advisable... following manufacturers guidelines... and use a good quality dust mask.... Arrow Airpen... The second airpen I use has an extended tip fitted and is not quite as heavy duty as the CP... it is great for intricate work, doing centres of ammonites or in between ribs, where the CP pen is proving to be too strong... I use this to great effect under magnification on small nodular material... it is very controllable... and adequate for soft matrix.... Follow manufacturers reccomendations regarding safety....as well as a good quality dust mask Mini Die Grinder... These are good as finishing tools for smoothing off the matrix when fitted with various small grinding stones... they usually have a 3mm collet so most dremel type attachments will fit into this tool.... unfortunately they have a rear exhaust which doesnt allow the dust to be blown away.... i tend to hold the tool one handed, and bend the exhaust tube round to blow back onto the work.... this has some success, but you find yourself stopping and restarting after having to blow the dust off.... a good quality dust mask is an essential bit of safety kit when using these, even if carried out ...outdoors....
  25. 13 likes
    The great Gerd Geyer has named a new species of Acanthomicmacca in my honor. Included among the various species of Acanthomicmacca are: A. walcotti, A. neltneri, A. hupei n. sp., named after Charles Walcott, Louis Neltner and Pierre Hupé. I’m especially grateful to be immortalized with some of the legends of trilobite research and discovery. Here is the abstract page with description pages and figures: Geyer, G. (2016) Taxonomy of the ‘Micmacca’ group, new Cambrian Chengkouiidae (Trilobita) from Morocco, and their bearing on intercontinental correlation. Australasian Palaeontological Memoirs, 49:329-393 ***Please send a PM with email address if anyone wants the entire 65 page monograph.
  26. 13 likes
    See below from Welton 1993: Your tooth is probably Orthodont and you are seeing the pulp cavity exposed because of tooth damage. Marco Sr.
  27. 13 likes
    Collectors, sellers on eBay and some dealers periodically ask me to help them in the identification of tyrannosaur type teeth. So I thought I would put something together to share my understanding of these teeth. I am focusing on teeth from the formations that are collected most frequently and available for sale. These include Hell Creek, Lance, Judith River, Two Medicine and the Canadian Formations of the western Provinces. Starting with the Campanian (72-83 mya) deposits there are three types of Tyrannosaurids present: Gorgosaurus, Albertosaurus, and Daspletosaurus being the largest. Teeth of these dinosaurs can exceed 4" (10cm) but most being sold or found are less than 3". Paleontologists views on identification of these teeth has changed over the years and is still evolving. A paper that came out in 2005 which was authored by Phil Currie et al. studied teeth from this period looking at tooth and serration morphology. Their conclusion was that "it is difficult to quantifiably distinguish these teeth reliably by taxon" . Bottom line, in my opinion, all these type of teeth should currently be identified as Tyrannosaurid indet. until further notice Having said that if you happen to be the proud owner of tooth around 4" its fair to say its probably from a Daspletosaurus. I'm not aware of any Gorgo or Alberto skull with teeth that large but have not seen them all. In the Maastrichtian (66-72 mya) deposits there are two Tyrannosaurid present: T-rex and the controversial Nanotyrannus Serrations need to be approximately the same size on both anterior and posterior sides Everyone is focused on the belief that T-rex serrations need to be under 2/mm for it to be a Rex. The facts do not support that belief. First the Campanian Tyranno study showed that tooth serrations do not aid in distinguishing between taxon and that study included juvenile T-rex teeth. Second, since I did not have a similar Maastrichtian research paper to fall back on I did an unscientific study with teeth from my collection. I sampled a dozen maxillary and dentary teeth from both Nano's and Rex's. Nano teeth ranged in size from 7/16" to 2" and Rex teeth were 1/4" to 4 1/2". I used both juvenile and adult teeth. (all counts were done over a 5mm spread on the distal side mid tooth) My findings were interesting and surprised me. In both species the number of serrations decreased in quantity as the tooth became larger. The serration count results: Nano's : Range from 4.5/mm to 2.7/mm Size: 7/16 to 1" : 4.5 to 3.4/mm 1" to 2" : 3.1 to 2.7/mm Rex's: Range 4.3/mm to 1.6/mm. Size: 1/4 to 1" : 4.3 to 3/mm 1" to 2" : 3.4 to 2.5/mm 2.5 to 3.5" : 2 to 1.8/mm 4.5" : 1.6/mm So how do you tell the difference between Nano and Rex. Well if its 2 1/2" or larger and has bulk its clearly Rex regardless of what the serrations say. It cannot be anything else. The problem arises with smaller teeth, you cannot go by serration count since they are similar. Clearly some small maxillary teeth will mimic each other and those have to be identified as Tyrannosaurid indet. However there are clear morphological difference in smaller teeth. The best way to distinguish these teeth is first in the cross section at the base and second compression Rex dentary teeth are oval at the base and you can see that in most maxillary teeth. Nano teeth are unique as tyrannosaurids go they are compressed and their cross section at the base is rectangular. A good technical way to see Rex teeth is that they are fat. Here are examples of the cross sections of couple small Rex teeth under 1 1/2 inch and Adult Nano's Rex (teeth are oval) Example of the shape of these teeth at the base. Although these are tyrannosaurids from the Judith it's applicable to T-rex Morphometry of the teeth of western North American tyrannosaurids and its applicability to quantitative classification Article (PDF Available) in Acta Palaeontologica Polonica 50(4):757–776 · April 2005 with 762 Reads Nano (teeth are rectangular) Compression is other attribute. Rex - (teeth are fat) Nano (teeth are flatted) . So if you are comfortable distinguishing between the two you can own a Rex tooth at a price that is much more affordable than the big one. It will not be the statement piece but its still Rex. I have not said anything about the Tyrannosaur Aublysodon and still see premaxillary teeth, those without serrations sold under that name. This dinosaur is considered nomen dubium and teeth ascribed to it belong to other Tyrannosaurs. I also have not said anything about premaxillary teeth. These should all be identified as Tyrannosaurid indet. with one exception T- rex. If you have one where the length is greater than 1 1/2" it Rex and enjoy. These of course are my opinions and I understand that there is a different views by some on Nanotyrannus and that's okay. We will convert you someday
  28. 13 likes
    I'd like to announce that i have donated two pterosaur humeri to a Pterosaur expert in Dallas, Texas @ SMU (Southern Methodist University). Dr.Myers has described many of the Lone Star state's flying reptiles, so he seemed to be the best man for the job. Here's how i "found" these. I frequently will find myself on eBay trying to find good deals, fossils to prep and/or misidentified fossils. These happened to be the latter. A man had found these near Grapevine, Texas. And needless to say, he had no clue what he had found, but i did. I thought it would be a great opportunity to make a few bucks, so i bought them both for under $50. Sweet! Now to find a species to label them with for resale. Well a weeks worth of research had lead me to the simple fact that these could be (and probably are) a new species of pterosaur never found in Texas before. Ok, donation time. And I'm not going to lie, i spent a full day thinking about going to the dark side of just selling these for a crazy amount (kinda tough when you're living paycheck to paycheck to let a money making opportunity slip away). But i figure paleontology has given me SOOOO MUCH, and has literally shaped my reasoning, understanding, passion, etc. There shouldn't even be a question not to donate these to science, and the World. Time traveling and finding fossils is my therapy. And you can't put a price on that. Lol If these do turn out to be a new taxon, expect a reconstruction drawing from yours truly. And hopefully i can name it after my Son. ....and yes, i will be contacting the seller to tell him about his great finds, but only after i get more information on these. I will keep everyone updated. Charlie
  29. 13 likes
    Without visible inclusions or knowing where it was found, it is almost impossible to determine whether or not it is a coprolite. Most of the siliceous rocks identified in rock shops (especially those identified as coprolites from the Morrison Formation in Utah) are questionable. With coprolites, you want to consider the following: Shape - Is there evidence of sphincter (pinch) marks, intestinal folds, etc? Proximity - Was it found near body fossils, footprints, or a nesting area? Are there visible inclusions (bone, scales, etc.) Is it phosphatic? Carnivore coprolites primarily consist of calcium phosphate - the same mineral prevalent in bone. Does it contain backfilled burrows? Dung beetles create backfilled burrows that are sometimes visible when herbivore coprolites are cut. Does it contain undigested plant material? In my own collection, I usually classify specimens like yours as dubiocoprolites. I hope this helps.
  30. 13 likes
    I thought I would share an exciting Mazon Creek fossil that I collected on March 1st of this year and just split open today. This is an extremely rare legless amphibian named Phlegethontia longissima from Pit 11. For a Mazon Creek fossil collector, this is about as good as it gets. Amphibians are extremely rare in the deposit and most collectors never find one. I have been collecting these fossils for over thirty years and can finally check it off my bucket list. It has been estimated that only one in five hundred thousand Mazon concretions will contain an amphibian. It needs a bit more cleaning and is fairly complete. The ribs, teeth and skin impressions are clear under magnification.
  31. 13 likes
    Sorry @JohnJ. East Coaster here, so I was asleep when you asked me what my experiences are. So, here you go. I've been collecting dinosaur fossils exclusively for the past 6 years. I'm a dentist, so I like to collect dinosaur teeth by nature. I have dinosaur teeth from 18 different species in my collection. Not as many as @Troodon, but a decent collection. At one time, I had around 15 or so Nano teeth in my collection, and maybe 6 or 7 different T.rex teeth, including a tiny rooted one that is less than 2 inches. I've actually given away most of these teeth to kids and other collectors over the years. I just gave one of them to a friend of my son for his birthday, another dinosaur lover just last week. So, I'll ask you a question: Have you ever paid $1300 for a tooth that was sold as a juvenile T.rex tooth, only to learn later that it was actually a Nano, worth less than half as much? Well, I have, 6 years ago. It isn't a lot of fun when you have to swallow that pill. So, when that happens to you, you take the time to learn the differences. Unfortunately, I was asleep, and Troodon answered much of it, but I'll add a few things:. First of all, when anyone sees the words "juvenile" or "Sub-adult", especially when referring to T.rex teeth, that should bring up a red flag immediately. The serrations on this teeth are too delicate to prove that it is from a T.rex. The serrations on even the smallest of T.rex teeth, are much more robust. When going toward the root surface or base of the tooth, you can see from both photos that the tooth clearly flattens, indicative of Nano teeth. I am certain that if a photo of the base were provided, you would see that it is rectangular in shape , and not the thick D-shape that a T.rex tooth has. Anyone selling a T.rex tooth knows that a photo of the base of the tooth is imperative. No one should purchase a tooth without that photo. Sorry, but I try to be a bright spot in this hobby that is full of greed and deception at times. I wasn't going to share this in the forum, but I think it is appropriate now to share it. Last summer, a little boy, probably 8 years old from Colorado, found a 5 or 6 inch T.rex tooth while digging with Walter Stein and Paleoadventures. His Mother posted pictures on the Facebook fossil forum. I asked whether or not he got to keep the tooth, and she said that he didn't. It was scientifically important, and he had to leave it with Mr. Stein. That bothered me that he didn't have a T.rex tooth of his own. Recently, I was very blessed to be able to purchase a fully rooted T.rex tooth. So, I contacted Walter Stein, who was gracious enough to make the arrangements, and yesterday, this young boy received a very nice 3 inch T.rex tooth that was in my collection. The look on his face said it all. So , in closing, I choose to alert others and be what is right with this hobby. It's what makes me, me. .
  32. 13 likes
    Continuing further down my diminishing stack of sifters, we are now at the 1/30" mesh size and the amount of material at this level is pretty small. I had tried to remove most of this fine material by using a 1/20" mesh size window screen as my bottom sifter when collecting the micro-matrix. This smaller material is just what was holding onto something larger while wet or didn't get completely cleared in the field during collection. There is so little of this that I ditch my methodical method of laying a ring of micro-matrix around the edge of the plate and just dump it into a pile in the middle of the plate. Some shaking and tapping spreads this out well enough and I switch to my higher magnification photo loupes (a 4X or a 10X) and do a quick visual scan to see if anything interesting pops out. Here is what it looks like zoomed in with my camera. Mostly, we are approaching the sand grain size at this point so it is mostly sand, fine shell hash, and a few tiny bits of black phosphatic material. A quick search did come across a tiny little oddity that looks like a microscopic version of something Queequeg would have launched at Moby Dick. Anybody recognize this? The tip of my dental pick for scale--it's tiny whatever it is. Below this, the remaining screens down to 1/100" mesh just pick up tiny amounts of what is basically dust. You can see from the coloration that this is mostly composed of a tan silica sand with a peppering of black phosphatic dust. The greater amount of sandy material at this granularity tends to inhibit searching for anything novel but I'm assuming if my micro-matrix contained something like very fine shark dermal denticles that they might start appearing at this level (or the one above). So far nothing of interest has appeared at this ultimate dregs level in the sifting process. It is quite nice to have this sandy material removed from interfering with the previous coarser sifting grades. It takes a bit more time to run the micro-matrix through the stacked sifters and collect each grade in turn for searching but I believe that effort is more than made up for by the efficiency gained in searching through the micro-matrix one size-class at a time. The chances of missing a tiny fossil being obscured by a larger piece of the micro-matrix are mostly eliminated by this pre-classifying before sorting through each grade in turn. I'm happy with my purchase and I believe it will not only aid my sorting through micro-matrix as a diversion when I get tired of typing long posts on TFF but it may also help me in the field while I'm collecting micro-matrix. I'm thinking of using the 1/50" through the 1/100" mesh screens instead of my 1/20" piece of window screen mesh. Though I will likely end up taking back home more sand in the process, I'm hoping that I might discover some interesting truly microscopic micro-fossils that I've been missing up until now. Hope this illustrated accounting of my new optimized micro-matrix sorting may be of some use to others on the forum who know the joy of tiny prizes hiding out of sight in a plastic Solo cup. Cheers. -Ken
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    To be clear (or at least a bit more so) species are grouped according to shared similarities (which are called synapomorphies). For example all mammals have hair or fur and females produce milk to nurture their young. No other vertebrates have hair/fur or produce milk, so these two traits are synapomorphies that unite all mammals. It is assumed that synapomorphies evolved one time, and so their presence in multiple species indicates that those species evolved from a common ancestor that first evolved the synapomorphy. Features that evolved over and over in otherwise different groups are not synapomorphies. For example amongst vertebrates both bats and birds have wings, so "wings" are not a synapomorphic trait. However when such structures evolve independently they will differ in many details of their construction, and those details may themselves be synapomorphies. This process of emphasizing shared synapomorphies in grouping species produces groupings that reflect shared common ancestors, and so reflect evolutionary history (phylogeny). As new data (such as new species) are added to the analysis, ideas about whether a structure is a good synapomorphy versus a feature that can evolve independently multiple times can change, and that will change ideas about phylogeny. For example, at one time it was assumed that serrations on teeth were a good synapomorphy, but accumulating evidence indicated that serrations have been gained and lost independently in various lineages of sharks, and so it is not a good synapomorpy on which to base hypotheses about phylogeny. Species are differentiated based on unique distinguishing features. Differentiating species is distinct from grouping species into higher order classifications. What is artificial is the creation of categories of higher order groupings into genera, families, and so on. Of course we need such groupings in order to be able to name different levels of clustering of species. If you think of a tree, the trunk gives rise to branches that give rise to smaller branches that give rise to still smaller branches all the way down to twigs at the end. In naming species, genera, families, and so on we are starting at the twigs (species) and working our way back towards the trunk (Kingdom). If you look at phylogenetic trees you'll notice that they don't have consistent levels where branching occurs. Just like a real tree, phylogenetic trees branch at different rates and it may be somewhat arbitrary to decide where to draw the line between different categories. The Linnean classification scheme is a way of putting a name on the different sizes of branches. It is very useful for naming groupings that reflect the phylogenetic history of species. It is arbitrary in that what is called a genus may differ from one cluster of species to another, there is no rigidly defined amount of similarity/difference between species that demands that they be grouped together in a genus, or that a genus be split up. Don
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    Nice tooth! It is indeed an early chimaeroid (shark-like cartilaginous fish) tooth. A bradyodontid type chondricthyan to be more specific. The "spots" that you see on the crown of the tooth are called bradyodont structures, but if you want to be more scientific sounding, call them "tubular trabecular dentine." These "spots" are a sure sign of this being a tooth. To learn more about the dentine structures of early fish, you should get the Handbook of Paleoicthyology Volume 3A. It is an awesome resource for anyone who collects these teeth. As for a specific ID, that is very hard. These teeth look different in every part of the mouth so there is a lot of cross-identification between different genera. However, if I was to put an ID on this I would say Lagarodus sp. That is tentative, but given the shape and structure of this tooth, it seems like a reasonable guess.
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    The bumpy surface reminds me of an ammonite aptychus. Not so sure the other side resembles one. Here is an aptychi from the Oceans of Kansas website-
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    A couple of Metacarpals were found. The extraction process is the same has with the larger bones but do not requiring jacketing. Foil is sufficient. Carpal 1 Carpal 2 Did not glue sections easier to prep since there is no glue. Teeth: T rex 2 inch rooted tooth was found missing tip. Don't think it was there but did collect a bucket of matrix and will keep my fingers crossed. Fragments of other teeth plus the rooted one Nanotyrannus largest 1 1/4" Paronychodon - largest 1" Acheroraptor - largest 1/2" Theropod indet - largest 3/4" Croc teeth and scutes - largest scute 1" Hadro Teeth - largest 1" Fish vertebrae - mostly gar - 3/8" Trike spitters Now the fun part begins hours and hours prepping everything to make them look presentable and like something you see for sale or in the museum
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    Leg bones are common and in this trip collected two tibia's both quite long about 3 feet. The process is typical expose the bone, pedestal it, wrap it in aluminum foil and then jacket it to make transporting it easier. In the hard clay takes around 3 hours to get one out. On this one the front end was very solid and I removed it to make jacking easier. I use tools to flip the bone to minimize any possibility of the bone sticking to the matrix Perfect all we have is matrix chunks visible. Second tibia I was happy to be able to find a couple of foot ungals which are not common . The first one is 4 inches long. You can first see what is exposed and I have no clue what it is. Very happy to see an ungual shape. The ground was wet so the matrix is attached to the bone making it hard to see. I took it out in a block to avoid any damage to the ungual being damp. Ungual two was found by hitting one of its wings "ouch" but I have the piece and will easily be repaired and wlll be very nice when cracked filled. I was also fortunate to find a couple of nice toe bones An infant one which is my favorite.
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    I find lots of caudal vertebrae while digging. Its always good to know the anatomy of one it makes for a happier ending instead of putting your knife through the spines of one . For example: Here is a centrum that I uncovered. Knowing where the spines is the next step. The clue here seeing the attachment surface for the chevron "C" . So if that's the bottom of the vertebra the spines and on the opposite side "S" . Like all bones we dig around them and down to pedestal them and then we can easily remove them. The bone can easily stay attached to the matrix if you don't and that would be a bummer The distal spines are very fragile and often break. I collected this with the spine off and centrum in aluminum foil. No reason to attach the two in the field just makes prepping harder. Vertebra 2 same story, where are the spines? In this position you are looking directly into the centrum. The clue here is that you can see the ventral side, bottom, of the vert being flatter so the spines are in the opposite side. Extraction process is the same. Unfortunately did one did not have a distal spine attached to it, missing in action Vertebra 3 is a tiny one 1 inch across from a juvie.. Its best just left in the matrix so I harden it with glue and extract the block. Vert 4. Sometimes they just pop out like this one. Its all there with one of the spines needing to be reattached. Its a odd vert and may be pathological since the centrum is offset. Vertebra 5, Here is one 4" across missing the distal spine. Centrums are common here is an assortment of finds including finger "carpal" (lower left) and toe bone (lower right) Big vert is 4" across.
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    Fake Dinosaur eggs are popping up again from a Malaysian seller. Calls them Stegosaur Dinosaur eggs.... Stay clear A 3 3/8" Rooted Allosaurus tooth. Seller says it has great serrations and has not been repaired. Very pricy. Indeed the crown looks great however theropod roots typically do not look like that. They taper and have an indentation for the replacement tooth. I suspect the majority if not all the root has been reconstructed or highly restored. A 6 1/2 Monster Spinosaurus tooth. While the tooth is big not a good collector item. Tooth is real but the seller indicates minimal prep work. The work done on the tooth is awful. Lots of fill, the very tip has been added. It's hard to determine what portion of the root is real or matrix so the length is questionable. Here is a museum quality Aublysodon mirandus in the words of the seller. It indeed is a beautiful tooth but misidentified. Aublysodon is not consider valid any longer and since its is from the Hell Creek most likely a Nanotyrannus. Seller "Here is a scientifically important bone from the Hell Creek formation of Custer County Montana! This piece has amazing preservation with great bite marks" Having trouble seeing great bite marks, some light gouges but great bite marks may be a stretch. Draw your own conclusions.
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    Hey all, I've put together a new post in my series on paleontological research tips detailing a lot of the methods I use in photographing fossils for publication. Bobby http://coastalpaleo.blogspot.com/2016/02/paleontological-research-tips-part-3.html
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    Hi Bev These are good and - I think - interesting questions. The colours we perceive are the result of particular wavelengths of visible light being preferentially reflected or scattered, rather than absorbed by whatever they fall on or pass through. I’ll comment on sky colour question first since the colour of the sea is – at least in part – influenced by the colour of the sky (from reflection). The colour of our sky is the result of “Rayleigh scattering” whereby the gas molecules in the atmosphere scatter the shorter wavelengths of blue and violet light from the Sun rather more than the longer wavelengths in the orange/red area of the spectrum. Although water vapour in the air plays a part, the major effect is from the gaseous components (primarily nitrogen and oxygen today). As the sun sets, its light has to pass through a larger expanse of the atmosphere such that the blue and violet part of the spectrum is so completely scattered that we no longer perceive it at all and only the red and orange parts of the spectrum are visible. During the day, the sky is technically violet rather than blue (because that’s the shortest wavelength in the visible spectrum and the most prone to scattering). The receptor cells in our eyes which allow us to perceive colours (known as cones) come in three types but with sensitivities to overlapping wavelength ranges. The combination of blue and violet scattered light is only perceived as if it were blue (and white) light, so we don’t perceive the violet colour. The sky probably hasn’t always been blue. Assuming our belief that Earth’s early atmosphere was methane-rich is correct, the physics suggest that it would probably have had an orange cast during the day, becoming even more vivid at sunset. The sky probably got bluer as the oxygen levels rose between 2 ½ and 2 billion years ago and probably reached what we would call blue between 1 billion and 540 million years ago. So, yes it would have been blue during the Ordovician but perhaps not as blue as today. As for the sea... water is a very good absorber of all wavelegths up to the blue/violet end of the spectrum and the absorption effect plays a bigger role than is the case for sky colour. The blue/violet colours are again reflected or scattered and so blue is usually what we see from above. Tiny particles in the ocean also enhance that by increasing the reflection and scattering and there is further enhancement in that large bodies of water tend to reflect the predominant colour of the sky. Viewed from below, the remaining transmitted light is stripped of pretty much all the wavelengths apart from blue/violet and so the sea appears blue at least down to about 200 meters. Beyond that, it just gets darker until you get to about 2,000 meters where virtually no light penetrates. Green colours are usually the result of algae and other microscopic life with chlorophyll pigmentation (and algal bloom can also create unusual colours such as the “red tide” phenomenon). The observed colour is also modified by suspended sediments into dull grey and brown colours. Storms, river deltas, underwater subsidence or volcanism would all play their part (both now and in the past). I would think that all of the colours of ocean that we observe today would also have been present during the Ordovician for the same kinds of reasons and what colour you saw would depend on exactly where you were and what the topography, climate and nutrient composition of the water were in that area. Earth’s early ocean was rich in iron, which would have influenced its colour, but the iron was deposited on the ocean bed in huge quantities as oxide-rich ores between 3.5 to 2.5 billion years ago. Thereafter, iron content in the ocean played a less significant role in determining its colour and probably had little relevance by Ordovician times. What we know about Ordovician oceans is that they were what are called “calcite seas” with a geochemistry dominated by low-magnesium calcite (from animals and macroalgae with calcareous skeletons) and that they were effectively calcium saturated. At the beginning of the Ordovician, there was a strong greenhouse effect from carbon dioxide in the atmosphere and ocean temperatures were generally believed to reach around 45 degrees Celcius. Those are good conditions for algal blooms. The climate gradually cooled until, at the end of the Ordovician, we have massive glaciation, draining of shallow seas and a general fall in sea level leading to the Ordovician-Silurian extinction. The decaying remains of the fauna that died would likely have created a highly nutritient-rich ocean for algal bloom to thrive. Much of the Ordovician environment comprised shallow clear water over extensive continental shelves and fragile reef environments dominated by algae, sponges, some bryozoans and – later – corals. Many areas would likely have had crystal clear aquamarine water but there is also evidence for periods of complete reef collapse arising from global disturbances which would have had a significant but temporary effect on the ocean colour. Concerning floating plants… graptolites (which in Ordovician times included surface drifters) were colonial animals not plants. There is fragmentary and spore evidence for primitive moss-like plants of a kind formerly known as psilophytes that perhaps lived in shallow water with their sporangia protruding above it. These plants probably also began colonising terrestrial environments in the Ordovician, but there were no vascular plants as far as we know. Those didn’t appear until the Silurian. The evidence suggest that plant life in the Ordovician was dominated by microscopic green and red algae floating on or just below the surface of the water.
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    Posted are a few concerns I found wandering through the internet. These are but a few examples of the type of issues you may encounter. I send this out as a reminder if you're shopping for fossil presents of any kind. Sellers mis-identify material simply through lack of knowledge but it's up to the buyer to know what they are looking at. Don't hesitate to post interests BEFORE you buy. BUYER BEWARE when it comes to fossils of any kind. Seller wants huge money for this Saurolophus osborni lower arm from the Two Medicine Formation. Looks like a nice arm but some of his facts are incorrect. This species is not found in the Campanian of the Two Medicine Formation but the early Maastrichtian age of the Horseshoe Canyon Formation. Another key point is that it's very difficult to determine taxons from post cranial bones of Hadrosaurs especially in an fauna where multiple species exist. Nice lower arm from somewhere and from some unknown Hadrosaur. What's this seller thinking the "2 Medicine Man Formation" really attention to detail not one of his strong points. Someone tell him its the Two Medicine Formation. Maybe he watches lots of Westerns Seller describes this as Pachycephalosaurus in my opinion it's Thescelosaurus Seller is properly describing this beautiful jaw as Ornithischian but in detail description adds that it was discovered where many Pachycephalosaurus fossils were found giving one the impression it's Pachy. In my opinion it's Thescelosaurus. Teeth of these two species look similar inquire before you buy. I see a lot of these being offered or sale, nice Christmas gift. For those of you that are new to collecting the only thing real here are the crowns. Nice gift Seller is offering this Claw and Identifying it as Velociraptor from the Hell Creek Formation. It's a very worn Anzu wyliei hand claw.
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    These are pseudofossils; nodules slickensided by burial compaction: Guilielmites
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    Periodically you see theropod material offered for sale from Patagonia and to a collector that's awesome. Typically its specimens obtained before the embargo laws went into affect from Argentina. My experience in looking at what has been offered is that it's often mis-identified as to locality, age and species. Sellers put commonly known dinosaurs identification tags to their specimen like Carnotaurus with complete disregard to the actual age and locality of where that dinosaur was described. That may simply be the information provided to them but they don't verify it and it's easy to do. The reality is that theropod diversity in Patagonia is huge, over vast collecting areas, several provinces, numerous formations and ages. Understanding theropods from this region is just beginning and little is understood, sound familiar Identification of isolated teeth unless there is something diagnostic about the tooth is virtually impossible. I have a difficult time accepting the notion that local diggers knew all the science around what they were collecting, maintained accurate records and provided detailed information to foreign buyers. It was all about the Peso. A recent publication sheds some light on discoveries and I've attached a couple of images to help with diagnosis of the locality and age of specimens you may see offered for sale. Material from this region is very cool but be careful, don't let emotion take over. Just make sure it's was legally acquired and be prepared to identify it as Theropod indet. and don't be fooled that the name offered is valid. Be happy you're just having the opportunity to acquire such a rare specimen. Evolution of the carnivorous dinosaurs during the Cretaceous: The evidence from Patagonia Fernando E. Novas, Federico L. Agnolín, Martín D. Ezcurra, Juan Porfiri, Juan I. Canale
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    Ceratosaurus are one of my favorite Jurassic theropod Dinosaurs found in the Morrison Formation. Teeth of this and other theropods are commonly sold through online Dealers and Auction Houses and at Fossil shows. Just because a site/dealer sells Jurassic material does not guarantee accuracy. My experience is that its very difficult to identify isolated theropod teeth from this fauna and mistakes are made more than buyers realize. Juvenile teeth or adult ones that are not fully developed also make the task more difficult because the identification starts competing with smaller theropod dinosaurs. Variation of the teeth in the jaw also adds to the complexity. So here are a couple of observations by no means complete that might help prospective collectors/buyers. First and foremost any chance of identifying Morrison Fm teeth starts with SERRATIONS, SERRATIONS and SERRATIONS that are visible on both anterior and posterior surfaces. They can be worn and don't need to be complete just visible. This quality of tooth is harder to find and will cost more but you have a better chance of an identification. Serrations on Ceratosaur's teeth are found from the tip of the tooth to the gum line on both anterior and posterior surfaces. If you find that the anterior serrations only go 2/3 of the way down its a different species. I found a serration count of 2.8 per mm at the midline of the posterior surface of my teeth . (Best to check at least 5mm) A 2008 paper of Ceratosaur's teeth found in Uruguay also showed a similar count. CAUTION these counts are just general guidelines and are not diagnostic to any species and we are dealing with a small sampling size For comparison I found serration counts on my Torvosaurus teeth at 1.6/mm and Allosaurid teeth had the biggest variation at 2.2-2.6/mm probably because of tooth position and number of different type species. So it appears that of the big three theropods in the Morrison, Ceratosaur's have the finest(most) serrations. Closeup of Ceratosaur serrations I'll get to the bottom line fast... there is only one diagnostics way to determine that you positively have a Ceratosaur tooth, lingual grooves. These grooves unfortunately are only present on the premaxillary and the anterior three teeth of the dentary. The next photo shows what they look like. Last photo is that of a guaranteed Ceratosaur sp. tooth. If you would like to learn more about Ceratosaurs, bones and teeth there is a great soft covered printing. Ceratosaurs (Dinosauria, Theropoda) A Revised Osteology by Madsen and Welles by the Utah Geological Survey Its also available on PDF but the book is cheap and a great reference guide. If anyone has additional information to add to this please post it.
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    With the new data, the Paleozoic machaeridians could be excluded. I think, they might be fragments of Trachyceras multituberculatum ammonites, or plant material like Ctenozamites, Equisetites, etc., as they are mentioned in WANG XIAOFENG et al. THE LATE TRIASSIC BLACK SHALES OF THE GUANLING AREA, GUIZHOU PROVINCE, SOUTH-WEST CHINA: A UNIQUE MARINE REPTILE AND PELAGIC CRINOID FOSSIL LAGERSTA¨TTE. Palaeontology, Vol. 51, Part 1, 2008, pp. 27–61.
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    I'm recycling some content from a prior post to cobble together a quick, non technical guide to ID Ptychodus teeth. Many of the pictures below are from CreekCrawler. A few terms: transverse ridges = the lines going across the tooth crown = the abrasive "eating" surface of the tooth margin = the area around the crown above the root flat crowned, from oldest to youngest: Ptychodus decurrens low crown with ridges that split (bifurcate) to the end of the marginal area Ptychodus marginalis (polygyrus) crown only moderately raised ridges circle crown at marginal area and margin has a circular "finger print" pattern unlike decurrens Ptychodus latissimus few, thick, "sharp" ridges on the low crown little marginal area Ptychodus martini very low crown, unlike decurrens and marginalis the marginal area is rough or non existent and has no discernable pattern more ridges and generally more rectangular compared to litissimus high crowned, oldest to newest: Ptychodus anonymus small in general 10+ ridges rough margin crown lower than whipplei and more rounded than mammillaris Ptychodus occidentalis gently curved high crown at a slight angle to margin unlike mammillaris 10+ fine ridges ridges branch into the marginal area unlike anonymous Ptychodus mammillaris crown attached at a steep angle to the marginal area unlike occidentalis ridges are course and crown wider/squarer than anonymous marginal area has a circular pattern around the crown Ptychodus whipplei very high crowned, peg like transverse ridges generally do not extend to the margin Ptychodus mortoni the crown is pointed with ridges running together meeting at a single point at the top of the crown Ptychodus atcoensis (sp.) front to back (labial to lengual) median line thick ridges that form a "chevron" pattern recenly named by Shawn Hamm, previously Ptychodus sp. Ptychodus rugosus most rare Ptychodus at least in Texas, no pictures to post ;-) transverse ridges are rough and poorly defined, almost giving the ridges a heavily "rusted" outline Orginal post with some other great picks from kknight. http://www.thefossilforum.com/index.php/topic/14366-ptychodus-occidentalis/
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    It is a fertile Diplazites unita. Fully half the examples of this taxon found at Mazon Creek are fertile. The main feature which separates Diplazites from the other true fern taxa, is each synangium (sorus) is made up of six sporangium versus other true fern genera with 4-5. This example may or may not show this due to preservation, but the well marked, even synangium layout and united pinnules is diagnostic. Though you did not ask, the use of Pecopteris should be restricted to sterile examples of plants with pinnules connected by their entire base with rather rudimentary venation and importantly in most cases we do not know it's fertile form. The name Pecopteris as presently used, is a sterile plant form, not a natural group. Members do not need to be even a true fern. In most cases of true ferns where the fertile structures are known, the name is other than Pecopteris. This is becoming more the case all the time as progress is made in understanding natural plant groups. As with this case, the correct genus name is based partly on it's fertile structures. Aren't you glad you didn't ask. Hope this helps, Jack
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    As an avid trilobite hunter, I have always been fascinated by the trilobites from Morocco. One of my first trilobites was one of the ubiquitous Calymenes from Morocco, and I have always wondered what collecting there would be like. Having a bit of a break before starting my new job, I found a (relatively) cheap last minute ticket to Marrakesh from San Francisco, and set off for a weeklong collecting trip to the Anti-Atlas Mountains near the trilobite capitol of Alnif, Morocco. I found a local trilobite digger who was able to guide me around the many remote dig sites, with a focus on the beautifully preserved Devonian trilobites. After nearly 24 hours of travel to get to Marrakesh, I took an 8 hour bus ride to the town of Tinghir, where my guide picked me up and drove me another hour to the small town of Alnif. We went to many of the classic Devonian localities, including Jbel Issoumour, Mrakib, Oufaten, Atchana, Timerzite, and ended off the trip to find some of the common Ordovician Calymenes at Jbel Tiskaouine near town. The collecting was hard - I anticipated it being difficult but underestimated the level of effort required to find these bugs. Having spent a considerable amount of time digging in Utah, working the hard limestones of Pierson Cove, this was on a whole another level. Unlike the nice shales/limestones of Utah, the rocks do not split into nice sheets, but fractured randomly with no discernable bedding planes. This required digging out large blocks of limestone, and then using 3 lb hand sledges, these blocks were broken into progressively smaller pieces, looking for cross sections of the trilobites, which oftentimes only looked like a random squiggly line if that. These pieces were then pieced back together like a jigsaw puzzle, and carefully wrapped to ensure all the pieces were preserved. My guide was able to tell what type of trilobite it was and its completeness based on the cross section alone - something I would have never been able to do. After 6 days of digging, we ended up with close to 100 complete trilobites - including several Phacops, Cyphaspis, Gerastos, Hollardops, Leonaspis, Cornuproetus, Crotocephalus, Odontochile, Scuttelum, and Walliserops, and of course several nice Calymenes. I now have a world class collection of (unprepared) Moroccan trilobites. I have my work ahead of me - it will likely take me years before I have the time to prepare them all. It was an amazing adventure, but not one that I will likely repeat in the near future, given the distance from the West Coast. And overall, the collecting was less enjoyable than I had hoped - swinging a 3 lb hand sledge for hours on end to look for a faint trace of a trilobite just wasn't nearly as rewarding as my experiences in collecting in Utah, where complete trilobites would pop out with the swing of a small brick hammer. I now have a much greater appreciation for the work and effort that goes into securing one of these amazing Moroccan bugs. I'm happy to share information with anyone who is interested in a similar trip - feel free to PM me. I may also consider a trade for some of this unprepped material - but given how much blood sweat and tears it took to get this stuff, it might take a lot of convincing. Here are a few pics: Jbel Issoumour near Bou Dib - you can see the light grey Psychopyge couche layer running for miles Jbel Mrakib - found many Cyphaspis here A typical trilobite found in cross section from the hard limestones - I believe these are two Phacops Working the hard limestones at Jbel Oufaten A nice Scuttelum from Oufaten Atchana - where backhoes have been brought in to expose the trilobite layer several feet below the surface Phacops from Atchana - you can see the detailed schizochroal eye popping out The workings at upper Atchana A nice Paralejurus from upper Atchana The scenery reminded me a lot of the House Range in Utah - except you see these guys Working the Harpes Couche of Jbel Issoumour Another view of the Psychopyge couche of Issoumour - it has been trenched for miles and miles I found these two nice complete Hollardops as float while walking around the trenches of the Psychopyge couche - pretty rare to find them exposed to this extent just lying around Jbel Timerzite - found several nice Walliserops and Leonaspis here that will take a lot of preparation. The town of Timerzite can be seen in the background. Jbel Tiskaouine - where the Moroccan Calymene trilobites found in shops all over the world are from Sorting all of our finds at the end of the trip - I was barely able to fit it all into my one checked bag and carryon bags.
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    Mike ... No problem.... I just hope it gives an insight into the tools available for people thinking of prepping their own fossils.... As with everything its practice, so dont start on your best fossil.... have a go at some broken pieces first.... Theres a couple of pen techniques I use besides using it as a point to cut into the rock.... The first is planing or skimming the rock off...which you can do when you start getting close to the fossil, maybe a couple of millimetres away.... It involves angling the airpen so the point is just litterally touching the surface skimming a very fine layer of rock away almost as dust.... you can very easily control this when you get proficient and it saves scarring the fossil as your not pressing in at an acute angle... couple this with a colouring in motion moving the pen across a cem or so and progressing forward... it becomes quite effective at removing the rock...If you have a decent air abrasives kit this is what you would use here, but I dont have that yet, so i have had to adapt what tools I do have .... to do the job... Planing/Skimming the rock The second technique I use is for digging down to get deep centres out say on a nautilus... I move the airpen in a circular motion covering a half centimetre diameter area, and am digging down at the same time... The front exhaust of the airpen usualy clears the debris, but you need goggles as it usually blows back straight in you face... Both these techniques need practice as the last thing you want is to scar the fossil....Ive got some images of a double ammonite I did a while back to show you the progress or steps involved... If I remember right it took 90 hours to complete it.... The lower images show the polishing of the calcite and the amount of centre that was missing due to crushing during fossilisation and reconstructed, carved within the rock..... Anyone fancy doing anything on Air Abrasives.... im all ears....and I hope this what those were interested was looking for....
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