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Showing most informative content since 03/02/2017 in all areas

  1. 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.
  2. 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. .
  3. 11 likes
    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
  4. 11 likes
    I'm pretty sure you are looking at the cross section of a rudist. They were strange looking colonial bivalves that formed reefs — some of which are part of the Edwards formation found south of Glen Rose, TX.
  5. 10 likes
    It appears to match well with Haskinsia (=Drepanophycus) colophylla Grierson, J.D., & Banks, H.P. (1983) A new genus of lycopods from the Devonian of New York State. Botanical Journal of the Linnean Society, 86(1‐2):81-101
  6. 10 likes
    Your Ray barb is actually a dorsal spine of a chimaera (ratfish). It's a nice find.
  7. 9 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
  8. 9 likes
    It's a gomphothere tooth, no doubt about it. The trefoil shape of the worn lophs are unmistakable.
  9. 8 likes
    A couple things about this idea. It's extremely unlikely that the claws shown at the top of the thread are from pterosaurs and almost impossible that they belong to azhdarchid pterosaurs (the family that Quetzalcoatlus belongs to). Among azhdarchids with known claw material, the length to height ratio of claws on both the manus and pes are generally pretty close to 1:1. This makes them short and stubby, not long and smoothly recurved like theropod hand claws. On a couple azhdarchids, the claw on digit 3 is a bit longer, but it has an unusual, almost "pinched" shape that is very unlike a theropod claw. Also, the first phalanges of azhdarchids have a weirdly "bulbous" shape and I've never seen anything remotely like them from the Kem Kem. It's also worth noting that you can't generally assume pterosaur parts scale in a linear fashion. In other words, a pterosaur twice as big as another member of the same genus or even species will not have bones that are simply twice the size. This is especially true for azhdarchids since the claws are almost comically small compared to the proportions of other bones in the wings and legs. One other thing. There is no evidence at all that pterosaurs "hooked on" to cliffs. The image was widely spread in the late 19th century when it was assumed that pterosaurs were morphologically similar to bats, but there is not only no evidence to support this, modern studies show that pterosaurs had a very different lifestyle. Footprints show that at least some species were effectively bipedal. In general, the idea that pterosaurs hung off of cliffs was just a bad assumption from a time when it was thought they were gliders and incapable of powered flight.
  10. 8 likes
    Carbon-14 is not biologically created, it is generated by cosmic rays colliding with nitrogen in the upper atmosphere, especially at high latitudes where the Earth's magnetic field curves down to the surface and allows cosmic rays to penetrate the atmosphere more effectively. Subsequently C14 can react with oxygen, initially to form carbon monoxide but that oxidizes to for CO2 which becomes dispersed in the atmosphere. Plants use CO2 to produce sugars and subsequently other biomolecules, so plants (while alive) are at equilibrium with atmospheric C14-CO2, as are animals that eat those plants. This equilibrium is maintained as long as the plants (or animals) are alive, as (1) those biomolecules turn over, which is to say they are recycled and replaced with newly synthesized biomolecules, and also (2) the lifespan of almost all plants and animals is very short compared to the half-life of C14. When plants or animals die, they cease taking in CO2 (or fixed CO2 in the form of plant or animal food) so their C14 content is not being replenished. From that point on, their C14 content will decrease according to the rate of radioactive decay, which generates a half-life of 5,730 (+ or - 40) years. After about 10 half-lives the content of C14 becomes too low to measure accurately, which puts a limit of about 60,000 years for useful dating by C14 content. Note that this process is a bit more complicated in actual practice, as it is known that the rate of C14 production varies somewhat over time due to solar activity and the generation of cosmic rays. This can be detected and corrected for by measuring C14 in ancient tree rings of precisely known age, and applying that correction factor to other types of samples such as bone. The half-life of C14 is very very short compared to the age of almost all carbonates. For example, a 50 million year old Eocene limestone will have gone through over 8,726 half-lives, so the C14 content remaining would be 1/28,726th what it was when the limestone was deposited. This is far below any possible detection limit, and in practice it is doubtful that any C14 would make it from a carbonate deposit into a piece of organic material with which it had contact (say via ground water). Don
  11. 8 likes
    I agree with jpc, one possibility is a caudal vertebra from a sauropod. The length works and with both ends being flared out a centrum is a good possibility. Here is a picture of that vertebra and what I have pointed to in red could be the attachment points for the spine. Here are a couple of screens shots of Diplodocus caudal vertebrae to compare against. Lots of different sauropods in Wyoming so it does not have to be this species
  12. 8 likes
    There were 3 types of ammonites that I found. Pictures just do not bring out the colors that these ammonites possess. I tried multiple types of lighting, but nothing worked to my satisfaction. First and rarest were Hoploscaphites nicolletti: Next were the most delicate Sphenodiscus lenticulares:
  13. 7 likes
    I had the distinct honor of guiding Jim Cox (jgcox) and his wife Kim yesterday as they toured Texas for family and fossils. The Glen Rose marine exposures north of San Antonio would have benefitted from rain to wash away the scratchings of other enthusiasts, but with a little diligence, we were able to assemble a burgeoning sack of goodies for their personal collection. We all found targeted Leptosalenia texana echinoids, and it was fun to be within feet when they each found their first. Jim's first one shown below. Jim is a Viet Nam vet and Purple Heart recipient, so helping him find some cool fossils is one small thing I can do to express gratitude.
  14. 7 likes
    According to this website, Besom Hill is Upper Carboniferous in age. It also notes that goniatites are frequently found there. I think I can see simple sutures on the item, so goniatite sounds correct. Neat finds - those should prep out nicely. Regards, EDIT: This book on Google Books mentions the genus Goniatites reticulatus and Goniatites gibsoni
  15. 7 likes
    It is a tooth from a cladodontid-type shark called Symmorium sp. The side exposed is the back side. It looks like it is from the Bangor Limestone which is found throughout the Huntsville area. Nice find by the way!! Edit: Additionally, I should mention, this tooth is likely from the Late Mississippian, so it is approximately 330 million years old.
  16. 7 likes
    No doubt, there is a longitudinal section of a radiolitid rudist lower valve. My guess would be Eoradiolites sp. Here is an example : Eoradiolites jumillensis n. sp. Longitudinal section (AV-PD) of a paratype specimen (10940-2) showing the abrupt modification (arrows) from deflected to oblique growth plates and the flattened LV bearing the posterior myophoral plate and extending to the shell edge of the RV (G1, G2) reference: J. P. Masse. 2007. Late Aptian-Albian primitive Radiolitidae (bivalves, hippuritoidea) from Spain and SW France. Cretaceous Research 28(5):697-718
  17. 7 likes
    Sorry but if you collected this in Hill County you are in the Judith River Formation which does not have T rex's. Rex's are in the Hell Creek Formation which is further south and east. It is a Tyrannosaurid but identification beyond that is impossible. Two candidates possible is Daspletosaurus and Gorgosaurus. Albertosaurus is possible but from younger strata. Still very nice.
  18. 6 likes
    The Hell Creek/Lance Formations have been very slow giving up their dinosaur secrets. Very few articulated skeletons have been found other than the king T rex. A couple of recent finds may increase the number of Caenagnathids in these fauna's. Caenagnathids are part of a group of bird like dinosaurs that are known by their easily identifiable hand claws. Currently only Anzu wyliei is described and accepted from these formations and is known from two partially articulated specimens and is the largest Caenagnathid in the fossil record. In 2013 a new species was was described from the Aguja Formation of Texas: Leptorhynchos gaddisi. Bones recovered from the Hell Creek of eastern Montana have similarities to this species and have been described as Leptorhynchos elegans but there still some uncertainty over that find. The current North American view of Caenagnathids is shown below In August of 2016 a presentation was made at CSVP by David Evans et al. on a new large bodied Caenagnathid that was similiar to Anzu wyliei. The finds were fragmentary but could not be assigned to A. wyliei with expectations it was a new species . Artist (Paleop) rendition of these dinosaurs. Impact on collectors.... Hand and foot claws are typically what you see sold as Anzu wyliei. The hand claws I have in my collection are not all identical and now could be explained by these different species. In fact I have a jumbo toe bone that just did not fit A. wyliei but may be perfect for this larger foot specimen. Also specimens sold as juvenile A. wyliei may just be something else. No hand or foot claws claws have been discovered in the Hell Creek with these new finds so it's uncertain if they have a different morphology. Bottom line to collectors and a common thread is that identification of isolated bones to a species level is very difficult and problematic. We are still in the discovery phase in the Hell Creek/Lance Formations and have lots to learn. One prominent paleontologist suggested around 5 Caenagnathids in these fauna's. Purchase and collect specimens because they are cool, unique and special but don't get hung up in the name. The hand claws are very cool. From my collection and collected in 2014
  19. 6 likes
    Bottom , 2nd from left is a turtle nuchal scute -- turn it over http://www.fossil-treasures-of-florida.com/nuchal-scute-tort011.html Bottom - 2nd from right is softshell turtle shell Directly up to the left of softshell turtle is a fossilized broken sand dollar (I know where you were digging - There is only one place to find these) Left and up from Sand Dollar is an endocast of a seashell -- it is not mammoth Center far left is a fragment of a C. Megalodon Center 2nd from left is a fragment of dugong rib That is half, I would have to see better pictures of the rest Shellseeker
  20. 6 likes
    Absolutely the most improbable, remarkable and weirdest of all.
  21. 6 likes
    Yes, this is turtle. Looks like it might be thick enough to be Hesperotestudo.
  22. 6 likes
    It's a trace fossil of a brittle star, made by the arm when it was crawling. Pteridichnites biseriatus, Brallier Formation.
  23. 6 likes
    Here's what I got from Maisey: Yes, skull roof, teleost of some kind (great, that narrows it down to 50% of vertebrate spp!). Presumably these fossils represent taxa that are still around. Unfortunately I don't know enough about teleost skulls to be much help. [Maisey specializes in chondrichthyans]
  24. 6 likes
    I would lean toward a Baenidae type turtle. That what I call the ones in my collection.
  25. 6 likes
    Looks like the cavities are from brachiopod imprints. Possibly spiriferids. The "serrations" are the remnants of the plications on the shells.
  26. 6 likes
    This is an exoccipital of some kind of ungulate, and is a particularly close match for a pig. Peccaries do not appear to have the enlarged mastoid process, which is the funny rod that is sticking off; the articular surface is the occipital condyle.
  27. 6 likes
    Not Tetraodontid. It is Diodontid. Very easy to tell the difference by the name. Tetraodontid means 4 toothed because puffers have two upper and two lower tooth plates. Diodontid means two toothed because the fish has a single upper and a single lower tooth plate. Diodontids include burrfish and porcupine fish.
  28. 6 likes
    Hi Bev, The name "Halysites gracilis" is an old name that was repeated uncritically in many field guides and geological papers that were not primarily concerned with coral taxonomy. At one point in time the name was automatically used for all chain coral specimens from the Ordovician of the midwest and west. At that time also, all "chain corals" were called "Halysites". Subsequent study indicated that there was significant variation of structure with the chain corals, too much to be encompassed withing a single genus. Today several genera of "chain corals" are recognized. One major feature is the presence of minute mesocorallites between the larger autocorallites that make up the chain. The autocorallites are the tubes you see with the naked eye, that are strung together to make up the chain. The mesocorallites can only be seen by making thin sections and examining the specimen microscopically. The old reference (1944) you cut/pasted from has the following definition for "Halysites gracilis": "Differs from H. catenularia in having corallites almost quadrangular in section and apparently lacking an intervening minute tube." I have underlined the important feature. All Halysites, as that genus is currently defined, have an intervening minute tube" (a "mesocorallite") between the large autocorallites. Chain corals that lack mesocorallites were assigned to a different genus, Catenipora. "Halysites gracilis" is an out of date name, it cannot be a Halysites even according to the description you posted as it lacks mesocorallites. You can read more about the issue in this 1955 dissertation by Edward Beuhler. In fact, even the name "Catenipora gracilis" has insurmountable problems. The original description by Hall was very cursory, so it is not clear how the species can be differentiated for many other "chain corals". Unfortunately the type specimens Hall had in hand when he wrote the description have been lost. Also Hall gave only a very general location for the source of the his specimens, so topotypes (material from the same locality) cannot be studied to gain an understanding of Hall's species. However, the "coup de grace" is that Hall's name (published in 1851) is a junior synonym, as that name had already been used for a different coral by Milne-Edwards and Haime in 1849. The unfortunate history of the name has been detailed by G. Winston Sinclair and Thomas E. Bolton [Journal of Paleontology, Vol. 30, No. 1 (Jan., 1956), pp. 203-206.] Once a name is used, it cannot be used for a different species. Specimens from the Red River Formation had long been called "Halysites gracilis"; since that name is invalid Sinclair and Bolton selected a holotype specimen from a well defined locality in Southern Manitoba and named it Catenipora rubida. It is possible that the specimen you found may also be a Catenipora rubida Sinclair & Bolton 1956, though to say so with confidence one would have to make thin sections and compare to the Red River species. What is certain is that the name "Halysites gracilis" is invalid on multiple grounds. Don
  29. 5 likes
    I was browsing the Internet and saw this vertebra for sale from my favorite locality the Kem Kem Beds. It's a good example of how the Moroccan's composite a dinosaur vertebra so I decided to post it. Here is the specimen and from a distance it looks acceptable. The centrum looks very nice and possibly a nice addition to a collection. Unfortunately after closer inspection everything else is questionable and red flags are raised. . Matrix fills the gap between the centrum and processes on both sides. Best conclusion is that all of the processes have been composited to the centrum. Is it possible that the processes belong to the centrum? Sure that's possible but another red flag is this bone. It looks nothing like an articulating process should look like and appears to be a peice bone that has been added to appear like one. Or are they adding it to be the neural spine which raises even more flags since the broken edges of one is already there. This vertebra is being sold as a Spinosaurus so it's always good practice to do a Google search and familiarize yourself with one. Scott Hartman's sketal drawings can be a good source. http://www.skeletaldrawing.com/ Not from Scott but here is an image of a dorsal vertebrae from a Spinosaurus. Compare it to the centrum in above specimen and draw your own conclusion. Identifying isolated vertebrae to a specific species from any locality is difficult enough. Identifying isolated centrums to a species is close to impossible especially from the Kem Kem. Comparative bones, images are just not available. Best to purchase a specimen because you like it and maybe someday it can be identified. For new collectors to the hobby always be cautious when you see matrix attached to a Kem Kem fossil. It's the media they use to hide imperfections, repairs and composites.
  30. 5 likes
    On a popular internet site is this absolutely gorgeous tooth out of the Hell Creek Formation in North Dakota. The tooth is perfect and the colors are stunning! The problem is that it is being sold as a juvenile T.rex tooth, and it is clearly a Nanotyrannus tooth. If it were priced at $300, I'd snatch it up in a heartbeat. Description says that it is too robust to be a Nano tooth. . Notice no picture of the base of the tooth is shown in the listing, so it's difficult for one to be 100% certain. Size is only 1.26 inches.
  31. 5 likes
    Possibly its this new undescribed Rinosaurus
  32. 5 likes
    No trade secrets !!! I first took a cast of the ammonites with elastomer (pict. 1). in this mould I poured hot wax and got a wax ammonite. I modeled with the same wax the head and the tentacles (pict. 2). When the model was ok, I took an second cast of the complete model with elastomer (pict. 3). In this second mould i poured synthetic resin and obtained a white solid model (pict. 4). i use this solid model for sand casting.
  33. 5 likes
    Superglue is good to use. Coat the broken surfaces with thin cyanoacrylate (=superglue). Then use thicker stuff to glue the pieces tpgether. Glue the two smaller pieces together first, the glue them to the bigger piece. A great way to glue things is to make yourself a wee sand box that you bone can fit into, with the broken edge facing up. Place this piece such that you can balance the piece to be glued on it. Then you can put your thicker glue on the piece that will balance, and place said piece into position. The glue will tend to flow downhill into the base piece (gravuty) and you can walk away and not have to hold the pieces while the glue sets. I call this a gravity clamp. Paraloud is also good, byt may be harder to find. if any of this is confusicating, please ask.
  34. 5 likes
    Well, I figured I might show what I've been up to, but I am unsure as to where this topic fits, so please do move this thread to a more appropriate forum if this subject is not fit for this one, Admins After my recent trip to Australia to see my fiancè and fellow forum member Ash, I had a fair bit of petrified wood laying around. The picture below only shows a small portion of the amount Ash and I collected, but I decided to take and cut the orange chunk in the left of the photo into slabs. I had just recently learned that the local rock shop in town actually had a "cabbing" machine, and in exchange for a few slices, I could use them for free to make cabochons of my own. So after shaping a few up onto "dop sticks", I did just that! I was rather surprised how different they turned out-how stunning compared to the original inconspicuous chunk of wood they originally came from! I also cabbed a few pieces of dinosaur bone the shop had laying around; you can see the end results in the photos below They're not perfect (I am a beginner), but just thought I would share how something that is often passed over in collecting can turn out stunning if you put a little work in The first single cab photo you see is the first one I ever did, and I have just recently had it wire-wrapped in sterling silver (the last photo). However, the last photo doesn't show the same quality as the first does due to poor lighting. Nonetheless, it's been a fun hobby to keep me occupied during the winter months I hope you enjoyed this brief update!
  35. 5 likes
    Since you have added this comment after I answered the initial question, now I will address this comment as well. The partial trilobite you found is certainly not Quebecaspis marylandica. Actually, it is not similar at all. To better illustrate the differences, I have attached 5 additional cranidia of Quebecaspis marylandica from Rasetti 1961. When compared side by side, it is quite obvious that Quebecaspis marylandica has a wide and large glabella. Also, the glabella of Quebecaspis marylandica extends to the anterior margin of the cephalon. The mystery trilobite has a narrow glabella that does not extend to the anterior margin of the cephalon. Ironically, Reinhardt 1974 mentions "ptychopariid, gen. and sp. undet." from the Adamstown Member of the Frederick Formation. Unfortunately, it is not always possible to ID a trilobite beyond a best educated guess, in this case an indeterminate ptychopariid. Reinhardt, J. (1974) Stratigraphy, sedimentology, and Cambro-Ordovician paleogeography of the Frederick Valley, Maryland. Maryland Geological Survey, Report of Investigations, 23:1-73 figures from: Rasetti, Franco (1961) Dresbachian and Franconian Trilobites of the Conococheague and Frederick Limestones of the Central Appalachians. Journal of Paleontology, 35(1):104-124
  36. 5 likes
    This looks like a Thylacocephalan arthropod - not sure what species, although Concavicaris georgeorum has been mentioned from the Mazon area. Fantastic fossil, Rob! Regards, Image from linked PDF below: PDF
  37. 5 likes
    Tabulate coral, something like Aulopora. There are also a couple of cross sections of rugose corallites on the left.
  38. 5 likes
    It closely resembles fossil bivalve shells that may be found on Vancouver Island, in both Cretaceous (Nanaimo Group) and Eocene or Oligocene rocks around Sooke and on the West coast of the Island. I lived in Vancouver for almost six years and collected quite a bit (though not as much as I would have liked!) on Vancouver Island, around the Princeton area, and I am familiar with the fossil collecting opportunities in the Lower Mainland. I have never seen, nor heard of, any fossil like yours from the Lower Mainland. If you found it in your back yard amongst other small rocks, I'm confident that it got there by being moved by people. Perhaps a previous owner picked it up while traveling on Vancouver Island, or farther afield such as the Washington or Oregon coast. Don
  39. 5 likes
    Thank you. First let me say, what others that frequent this forum already know is that identification of isolated bones even teeth from this fauna is very difficult. Other than Spinosaurids not much has been has been published and what is usually consists of very incomplete specimens or just isolated bones. I'm leaning away from this being a theropod vertebra more toward crocodilian but it's a guess on my part because I have nothing to compare against. Two features that jump out which concern me the most against it being theropod are the following. This is a proximal-mid caudal vertebra and you do not see them that long on larger theropods. They are usually more boxed shaped except for avian dinosaurs. Second, neural spines on theropod usually do not not have webs that's more typical of croc's, see photo. I would love to hear other opinions because the Kem Kem is always full of surprises and there is a lot of learning to be gained. It's a very nice vertebra and great collector item.
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    The critical reader may wish to explore the source of funding of this work.
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    It looks like a hyperostosed neurocranium of a fish.
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    This is an upper molar of neither Cimolodon nor Mesodma. Those are both multituberculates. In the Lance/ Hell Creek there are three groups of mammals...multituberculates, marsupials and placentals. This is one of the latter and, yes it is well worn. IDing one group from the other is tough, but marsupials had five little cusps on what is the right edge of your bottom shot,. I think I see two of them posted in my copy of your photo. Also, at 6 or 7 mm long it is very big so I am going to call it Alphadon, a big and common (relatively) genus in the Lance. There are many species and I cannot guess which it is without my books.
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    The only named sauropod from the Kem Kem is Rebbachisaurus garasbae an interesting fact is that it was initially thought to be a large bodied sauropod but now it's considered much smaller in size. The Titanosaurid is considered large bodied but not described any further, only a few vertebra have been found. Its has affinities to the Titanosaurid from Brazil, Baurutitan britoi . Late me restate, we know very little of sauropods from this region. What suppliers are selling is not based on any published scientific evidence and probably just based on the fact that we have a described name and teeth that look like they work. No skulls have been found with teeth.
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    I thought I had covered this. The carbon in your calcium carbonate was "fixed" when the rock was deposited. Rock does not breath, so atmospheric CO2 is not continuously incorporated into limestone deposits, for example. The carbon in an Ordovician limestone has been there since the calcium carbonate was deposited about 500 million years ago. In a Cretaceous chalk deposit, the calcium carbonate is formed of the minute shells of foraminiferans that lived in the Cretaceous (about 80 million years ago in the case of the White Cliffs of Dover for an example), died, and their shells settled to the sea floor to form an ooze that was subsequently compacted and dewatered to form chalk. The carbon in those shells was not exchanged with atmospheric CO2, nor have the shells grown and added new material, since the foraminiferan that made the shell died 80 million years ago. Any 14C that was present in that carbon has gone through so many half lives that (mathematically speaking) none of it remains. I think perhaps you are confused by experience with long-lived radioisotopes that are present as mineral deposits or an original component of the planet. Every atom of Uranium-235, which has a half life of ~704 million years, was formed in the core of a giant star and dispersed during a supernova, and so it has been a constituent of the planet since the Earth's formation. The conditions to make 235U do not exist on the Earth. This is totally different from 14C, which is continuously produced in the upper atmosphere by cosmic rays colliding with nitrogen. There is no source of 14C within the Earth, it is all generated in the atmosphere. Any 14C that may have been present when the Earth condensed from the cloud of gas and dust orbiting the sun is long gone, as that event was over 842,000 half-lives ago. The only possible way it can get into calcium carbonate is by the action of the plants or animals that pulled it out of the atmosphere and added it to their shells. Once the shell-maker is dead it ceases adding carbon to the shell, and the 14C that was put there begins its inexorable path to decay. Your comment about environmental calcium carbonate adding high 14C to the mineralizing fossil could only be true if the environmental calcium carbonate had been deposited within the last half-life or two of 14C, which is to say the organisms that generated the calcium carbonate were alive within the last 10,000 years at most. I cannot think of an actual geological context that this scenario would apply to. Moreover, if a fossil is buried in calcium carbonate (limestone), surely it is the same age as the limestone? How could limestone generate an anomalously young age for, say, a shell that is encased in that limestone, unless the shell is somehow much older than the limestone it is embedded in? 14C is only very rarely used to date fossils, such as unmineralized very late Pleistocene bones, because the half life is so short. Dating older fossils or rocks relies on other isotopes/radioactive decay series with much longer half lives. In such cases it is true that care must be taken to avoid sources of environmental contamination. One tactic is to use different elements, with different decay rates, to independently generate dates for formation of a rock deposit. If two or three different isotope series give congruent dates, there is a good likelihood that the date is correct. If ground water, for example, percolates through a deposit and leaves behind (or removes) certain isotopes, it is very unlikely that it will affect multiple different elements in exactly the same way, considering the differences in chemical reactivity, solubility, etc between different elements. In that case different radioisotopes will give divergent dates. These days, a lot of radioisotope dating is based on elements lock in zircon crystals, which are chemically inert and so are resistant to contamination. Don
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    Please be aware there's a bunch of supposed Ankylosaurus fossils on our favorite auction site. They are sold as Ankylosaurus armor, or tail plates. There are other similar pieces of maybe-fossils sold as Ankylosaurus parts, along with pieces of rocks sold as dinosaur eggs. I admit my knowledge in Ankylosaur fossils is limited, but I see absolutely nothing about these that's indicative of authentic Ankylosaurus fossils. No locality is given either. Please be on alert when you see these, along with the sellers' other suspect items. Real Ankylosaurus fossils should firstly be sold by a reputable dealer(since they are hard to identify properly), they should have bumps/ridges indicative of armor, and should have a rugose/wrinkled/bumpy texture. They are found in the Hell Creek Formation, Lance Formation, and Scollard Formation. Here are pictures of 4 authentic specimens for your reference.
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    Same age as the Hell Creek this one is the one of the most common in that fauna Myledaphus sp. denticle may be the same.
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    Latin was my favourite subject in school. The first week you never learn. 'My name is.....Where can I buy a loaf of bread?' instead its 'Caesar's army conquered Britain and ordered his army to set up camp and secure the perimeter with ramparts.' The first week I learned that place names ending with chester, ceister, caster, etc were all derived from the word meaning a Roman military camp. After that I was hooked. My girlfriend is from Man'chester' first founded as a Roman fort. Thread hijacked. Its a phalange from a Tyrannosaur but not possible to ID genus.
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    A possibility is Alokistocare americanum (Walcott 1916). The large number of thoracic segments and tiny pygidium is consistent with that ID. The species occurs in the Conasauga Shale at localities around Weiss Lake AL as well as in nearby Georgia. Schwimmer (1989 Journal of Paleontology 63:484-494) redescribed the species and synonymized numerous species described by Resser. The figure is from Resser 1938 and shows Acrocephalops nitida (20) and Acrocephalops insignis (28, 29), both species considered identical to Alokistocare americanum by Schwimmer. One issue that has led to oversplitting of trilobite taxa in the Conasauga is type of preservation: trilobites can occur flattened in the shale, partially flattened on calcite cone-in-cone wafers (the same way Elrathia kingi is preserved in the Wheeler Shale), or fully three-dimensional on or in chert nodules. Flattened shale specimens can have proportions significantly different from uncompressed chert specimens, and Resser was notorious for basing species on these sorts of taphonomic differences. Don
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    The Member Map here on TFF exists for finding members in your area. To plan fossil collecting trips, members usually post the location they're going to be hunting and date (or they ask a date that would work best for everybody that would like to go on the trip).
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    As I mentioned above about erosion being reduced by vegetation, here are three views of the "Tipple Area" that was shown on the first post of this thread. These three pictures are of the same area, but you can see how the landscape has changed. There are still tons of fossils out there, we just can't get to them. 1971 Tipple Area 1993 Tipple Area 2012 Tipple Area