Search the Community
Showing results for tags 'pridoli'.
Found 22 results
-
From the album: My collection in progress
Scyphocrinites elegans Zenker 1883 Location: Boutschrafin, Erfoud, Morocco Age: 420 Mya (Pridoli, Silurian) Measurements: 20x12 cm (plate) Kingdom: Animalia Phylum: Echinodermata Subphylum: Crinozoa Class: Crinoidea Subclass: Camerata Order: Monobathrida Family: Scyphocrinitidae -
This specimen was from my most recent collecting trip. It is from the Leighton Formation, which is Pridoli, Silurian. It was suggested by @Tidgy's Dad that it is likely a cryptosome, but I was hoping for a third opinion. The following pictures show the specimen. I have already posted some of these pictures, but have added scale (finally). The first two are of the two pieces of the specimen - I refer to the top image as the "external mold" in reference to the Nuculites bivalve next to it, and the second as the "cast". The last is a close up of the "feathery" section on the end. Thanks for reading!
- 1 reply
-
- 1
-
-
- invertebrate?
- leighton formation
- (and 3 more)
-
I finished this prep of a trilo-cephalon a week ago. I kept forgetting to post it, but I finally remembered today. This is an Acaste zerinae cephalon. It is from Leighton Formation, pre usual. It is missing a small chip of the right eye - I unfortunately didn’t notice its absence till I returned home. It’s a shame, this guy would have been completely whole if I had found it. On the plus side, this guy’s a very nice color in the sun - a kind of bluish. The other trilo-bits - including another cephalon - all were a brownish color. Makes this one a bit more special. The first picture below is of the cephalon pre-prep. All the following images are of the cephalon from multiple angles, then in natural light. Thanks for reading!
- 4 replies
-
- 7
-
-
- fossil preperation
- leighton formation
- (and 4 more)
-
The thread http://www.thefossilforum.com/index.php?/topic/84678-adams-silurian/ was getting rather enormous, so I have decided to leave that one to deal with the Llandovery and Wenlock and put my specimens from the Late / Upper Silurian here, though I don't have a great deal of material from the Ludlow and Pridoli yet. However, I do still have some jolly nice specimens to show off here. Here are my other collection threads for the Cambrian and Ordovician ; http://www.thefossilforum.com/index.php?/topic/78887-adams-cambrian/&tab=comments#comment-832018 and : http://www.thefossilforum.com/index.php?/topic/78974-adams-ordovician/&tab=comments#comment-832912 In the mid 1980's, on the way home from one of my annual visits to the Hay-on-Wye second-hand bookshops, I managed to persuade my girlfriend at the time to take a bit of a detour and stop off at a roadcuttting just outside Aymestrey,, Herefordshire in the Welsh Borderlands. The rock here is the Aymestry (sic) Limestone Formation, part of the Upper Bringewood Beds and is Gorstian, Lower Ludlow in age, so about 426 mya and a little younger than the Much Wenlock Shale Formation. Many species of coral, trilobites and brachiopods found in the formation are the same as those found at Dudley, but the bed is noted for its massive numbers of the brachiopod Kirkidium knighti (was K. knightii),a lovely, large pentamerid. In fact, during my hour or so searching, I found almost nothing but this species, the only exception being a couple of Atrypa reticularis. The problem was that this limestone is thick and seriously hard, even the broken bits are generally huge, but I managed to obtain half a dozen reasonable specimens and about the same number of fragments. Over the years I have traded, given away or sold them, so that now I only have the best one left. Here is Kirkidium knighti : It's a shame the tip of the beak is broken off : I make index cards for all my fossils, this is the one I made for the specimens at the time, back in the mid 1980's : And today's version : There was a minor extinction between the Wenlock and the Ludlow, known as the Mulde event and it is often said to have primarily effected graptolites and conodonts, but it seems to me it had a massive impact on the bryozoan faunas of the time too. Gone are the varied stony stick and mound trepostomes that made up such an integral part of many faunas from the Middle Ordovician through to the Middle Silurian and even cystoporid groups such as the Constellariidae became extinct at this time. Trepostomes and cystoporids did survive until the end of the Triassic, but were never as important again, the bryozoan faunas would start to become dominated by fenestrids in the Devonian, though they reached their peak of diversity and distribution in the Carboniferous. I will look closely at my limited number of rocks, but I don't think I have a single Late Silurian bryozoan. I know our friend @Mainefossils studies the Late Silurian Leighton Formation in microscopic detail, but I can't recall him posting any bryozoans. Are there any, Asher, old chap? Interesting.
- 28 replies
-
- 12
-
-
-
The brachiopod fauna of the Leighton Formation is so small that I don't often find one that needs some help with identification. This individual does. The closest brachiopod that has the same characteristics is Eoplectodonta (=Plectambonites) transversalis, but it only occurs in the Dennys Formation. The Dennys Fm has quite a different fauna from the Leighton, but it is the closest thing I could find. My other option was some sort of small spiriferid. I will have to defer to @Tidgy's Dad for this one. Below are two pictures of it, first of the cast, and second of the external mold. Unfortunately, the fossil is rather damaged - the split did not cooperate with it. It is from the Leighton Fm, which is Silurian, Pridolian. Thanks in advance for your help!
- 3 replies
-
- 1
-
-
- brachiopod
- eoplectodonta transversalis
- (and 5 more)
-
Well, it has been a while since a post on the Silurian Leighton Fm. Had to make a trip due to family matters, and once I got back had a lot of work to do. I finally got into a position to start splitting and prepping more shale, and found this new little guy. I am torn between an operculum of a gastropod, and an inarticulate brachiopod. My main argument for an operculum is because of the shape - the only inarticulate brachiopods in this formation are Orbiculoidea and Pholidops. Unfortunately, I cannot find any reliable papers on the brachiopod Pholidops, it looks very similar but there is quite a bit of variation. The gastropod Australonema (possibly Cyclonema) is found in this formation, and the operculum of the genus is very similar to my specimen. On the other hand, the rarity of such Paleozoic opercula make me think that this is a brachiopod. And now for the specimen itself. It was not found in association with any gastropods, but was next to numerous Nuculites bivalves, some ostracods, and a tentaculite. The pictures below first show the two opposite halves of the specimen - unfortunately one was damaged when the shale split. Thanks for reading!
- 4 replies
-
- 3
-
-
- australonema
- fossil identification
- (and 8 more)
-
This is a recent prep I undertook - a rather incomplete specimen of a Chonetes bastini, a species of brachiopod from the Leighton Formation. I picked this one as a practice piece to try some new techniques on, and was hoping for any tips on different finishes for the matrix. I have heard that beeswax was often used for the matrix to make it appear darker, but did not know the proper methods or appliance techniques. Any thoughts on the finished product are also appreciated! The specimen itself is missing the upper right left of its shell, and only has two spines present (upper right). Otherwise, it was a well preserved specimen. I applied a thin coating of paraloid to the shell, to make it stand out, as well as preserve it better. The pictures show the specimen before and after preparation. The first image is of it before prep, while the last two are of it after. Thanks for reading! @Ludwigia @Terry Dactyll
- 8 replies
-
- 3
-
-
- brachiopod
- chonetes bastini
- (and 4 more)
-
I am really puzzled on this new one, I have explored phyllocarids, trilobites, and many others, and can't seem to find a good match for it. I am not absolutely positive it is a fossil though, just the surface texture and way it prepped makes me think it is. It is from the Leighton Fm, which is Silurian, Pridoli. When I first started prepping this, I was under the impression that this was the internal mold of a Chonetes bastini, which is why I started on it. I soon discovered though that it couldn't be from a brachiopod, and now I am stumped on it. The first specimen is completely prepped out, it is labelled SA in the photo. In the process of prep, I also found a new piece that exhibited the same surface-texture (labelled SB in picture), and could be a part of the first specimen. Below are a few pictures of it. The first is of the specimen before prep - this is the only picture I have, and shows everything that was exposed. It was taken from the top of specimen SA. The next picture was taken from above, it shows the two specimens (SA and SB) and their relation to each other. The third picture shows the specimen that is on the upper left (SA), the fourth shows the specimen on the lower right (SB). Thanks in advance for your help!
-
So, I have just found this highly-suspect fossil - my guess is a conodont. I saw it as I was examining pieces of shale, and thought it was worth looking at under the microscope. It seems to have the diagnostic features, even the transition of colors between the blue base and white tips. I was hoping for some of your options on it. If this is a conodont, it would be the first from this formation. My guess would be a Ozarkadina sp - it is a very common Silurian conodont here, and some of the elements look remarkably similar to my specimen. This specimen came from the very fossiliferous layers of this formation, and was found in association with multiple ostracod species (Kloedinia, Londinia, Hemsiella, etc.), T. elongatus tentaculites, and Nuculites corrugatus. This formation is Pridoli, Silurian. Thanks in advance for your help!
- 8 replies
-
- 3
-
-
- conodont
- leighton formation
- (and 4 more)
-
I have just found this little coprolite? yesterday. This is the second time a coprolite-like fossil has turned up in the shale from the Leighton Fm. I am not really sure on this one, though, due to the presence of crinoid stems. The fossil(s) are from the Leighton Formation, Maine; which is Pridoli, Silurian. The main reason I think it is a coprolite is because of its situation in the shale. The rest of the shale around it is relatively uniform, with no fossils whatsoever. The fossils present in it are one crinoid stem, quite a few ostracods, a very small Orbiculoidea brachiopod, and an unidentified piece of rather bluish-black material in the center, possibly some sort of shell. My main concern for its identification as a coprolite is the wide range of rather large fossils in it. I don't know what animal would have had such a diet, except possibly a very large detritivore - but I don't know of any super large ones here. The only animals that I can think of producing coprolites in this formation would be eurypterids, phyllocarids, agnathan fish, and possibly trilobites. A coprolite of this size I would identify as an agnathan fish, but I would defer to some of our fish and coprolite experts for this. @jdp @GeschWhat Below are two photos of the two different sides of the coprolite. If you would like closeup photos of some of the fossils inside the coprolite, I have some available. Just did not want to overload this post with too many photos. Thanks in advance for your help everyone!
-
This morning I split this shale (technically it fell apart on me), and found this interesting little fossil. I was thinking that there was a possibility of it being a phyllocarid valve, but I have never seen one. This also raises a question that I have been wondering - how do you differentiate between a phyllocarid and a bivalve valve when the tail is absent? What raised my suspicions on this specimen are the raised bumps on the external mold and the depressions on the cast. The pictures below are of the specimen. The first shows the cast/internal mold, and the second the external mold. It is from the Leighton Formation, Maine; which is Pridoli, Silurian. Thanks in advance for your help everyone! @Fossildude19 @mikeymig
- 9 replies
-
- 2
-
-
-
- bivalve
- leighton formation
- (and 4 more)
-
I am unsure on the identification of this brachiopod. It is from the Leighton Formation, Maine; which is Silurian, Pridoli. According to Maine's Paleozoic Record (an excellent book that lists all the fauna and flora found in formations across Maine), there are only two Rhynchonellid genera in this formation, Camarotoechia and Rhynchotrema. It does not look like a Camarotoechia, but I cannot find many references for the internal mold of Rhynchotrema brachiopods. I would appreciate any references you have on this genus, as well as any advice on the identification of it (@Tidgy's Dad?).Thanks in advance for your help! Regards, Asher
- 4 replies
-
- 1
-
-
- brachiopods
- fossil identification
- (and 7 more)
-
I finished prepping this specimen recently, an unidentified Camarotoechia brachiopod. It exhibits an uncommon/rare orange coloration; only about 1/100 of Camarotoechia brachiopods show it. This one, though, unfortunately has some compression damage on the right side, and some of the ridges have pieces missing. The pictures below first show the pre-prep photo (which I finally remembered to take), and the post-prep. Thanks everyone for reading!
- 4 replies
-
- 6
-
-
- brachiopod
- camarotoechia
- (and 4 more)
-
I have a nice little gastropod in my collection, from my most recent trip to the Leighton formation. I am pretty certain that this is a Platyceras sp, such as the one shown in the plate below, figures 23 - 24. Boucot, A. J., Yochelson, E. L. (1966) Paleozoic Gastropoda from the Moose River Synclinorium, Northern Maine. Geological Survey Professional Paper, 503(A). https://pubs.usgs.gov/pp/0503a/report.pdf I do not believe that specimens such as these have been assigned to species as of yet, and would greatly appreciate to hear any insight on their taxonomy. The lifestyle of these gastropods is pretty interesting. It is thought that they attached themselves to the anal plates of crinoids, to feed on their excrement. There is some debate, though, that instead this species was a suspension feeder, or was parasitic, boring holes in through the crinoid's shell. The picture below is of my specimen. The tip, unfortunately, broke off, but the rest of the specimen is intact, though it is laterally compressed. It is from the Leighton Formation, which is Pridoli, Silurian. Thanks for reading!
-
- 2
-
-
- gastropoda
- leighton formation
- (and 4 more)
-
I have just found this microfossil. It is unfortunately incomplete, but the general shape is still discernible. I have two ideas for this specimen, a fish scale or an inarticulate brachiopod. Of these possibilities, I think that inarticulate brachiopod is more probable. The shape, "growth rings", and slight depression in the top lead me to this conclusion. On the other hand, its size, color, and the absence of such brachiopods from this formation, lead me towards fish scale. I am uncertain on both, and could use some help with this one. The specimen is the from the Leighton Formation, Maine; it is Pridoli, Silurian. Thanks everyone for your time!
-
I have found a few Tentaculites specimens from the Leighton Formation, Maine; which is Pridoli, Silurian. I was wondering if it is possible to ID them to species, based on the external molds alone. I have read in a few papers that many tentaculite species are identified by the number and shape of the rings on the shell exterior. Unfortunately, I have not been able to many definitive papers on USA Tentaculites sp, and their identification. The specimen below is only of the external mold. This is the best preserved, as well as smallest, of the specimens that I have collected. So, is it possible to ID this specimen to species, or is it not complete enough? Thanks in advance for your help!
- 2 replies
-
- 2
-
-
- fossil identification
- leighton formation
- (and 4 more)
-
I have just finished preparing this little fossil. I really have not seen anything like it. It reminds me of a eurypterid head fragment, or something similar, but the ridges on the "internal mold" are perplexing. Also, it is horizontally symmetrical, suggesting a scale or segment. It is from the Leighton Formation, Maine; which is Pridoli, Silurian. The pictures below first show the "internal mold" under raking light, than of it under direct light. The third picture is of the "external mold" under direct light. It does not have any surface detail that would be brought out by raking light. Thanks in advance for your help!
-
So, I have been preparing this nice little gastropod. I have seen five other specimens that shared the same characteristics, but, unfortunately, some of them did not make it. Before I continued to prep this one, I was wondering if it is possible to roughly ID this gastropod. It would greatly facilitate prep work to have a good idea of its shape. All the specimens I have seen have had three whorls. The upper two whorl's ridges are almost absent, this has been consistent through all my specimens. The shape of the shell is coeloconoid. It was found in the Leighton Formation, Maine; which is Pridoli, Silurian. The pictures below are of the specimen under direct, then raking light. The third picture is the external mold under direct light. Thanks in advance for your help! @MikeR @Rockwood
-
I have read in multiple papers that there are three theories to the preservation of thelodont scales. First, a rapid burial when the thelodonts have died under still circumstances, e. g., in a lagoon or other still body of water. This results in associated scales. Second, the thelodonts die and disintegrate in the open ocean, leaving behind disassociated scales. Third, the thelodonts were eaten, and deposited as coprolites. Now, I have just found an array of thelodont scales in a single small spot. The stone they are preserved in is a lighter color than the rest of the shale. The majority of the scales are Phlebolepis elegans, with one being of a Thelodus parvidens. I was wondering if it could be an example of a coprolite? It is from the Leighton Formation, Maine; which is Pridoli, Silurian. The pictures below first show the cross section of the specimen, and then the top of it. I will take pictures of the individual scales as soon as possible. It is rather hard to see the cross sections in the pictures, but the bluish pieces are thelodont scales. Unfortunately, I don't think it will be able to be prepped without destroying some of the details. Thanks in advance for your help! @GeschWhat @Rockwood @jdp
-
When I first started prepping this one, only the tip of the bottom right corner was showing. I initially that that it was a trilobite free cheek, which is quite a common find for this formation. About half-way through, I realized that it was not what I had initially thought. Now that I see it fully prepped, I have absolutely no idea what it is. Approximately half of it had crumbled before I started preparing it, due to the soft siltstone it was preserved in. Any help would be greatly appreciated. The pictures are taken with direct light, as there are no small details on the surface that will be shown with raking light. The scale shown is in millimeters. It is from the Leighton Formation; which is Silurian, Pridoli. Here are the photos:
- 6 replies
-
- 1
-
-
- fossil identification
- leighton formation
- (and 3 more)
-
I have been finding these small little fossils all through my specimens from the Leighton Formation, which is Pridoli. I suspect that they are myodocope ostracods, but I haven't found any ostracods that match it from my available literature. The specimen below appears to be an association of two valves. Each individual valve has a small protuberance in the middle, with two pits next to it; they are approximately 4 millimeters long, by 1.5 millimeters wide. The pictures below are first of photo with direct lighting, then a photo with raking light, to show the protuberances. Any help would be greatly appreciated!
-
Actinopteria bella is a species of bivalve found in the Leighton/Pembroke Fm, and first described by Henry S. Williams. It is differentiated from A. fornicata by less convexity in its shell and a wider beak. It is differentiated from A. dispar by its shorter shell. The above pictures are of the left valve. A poorly preserved original or cast of the shell exterior is on the left side. Some of the exterior of the shell may be missing since the exterior ribs have less than normal height. The right photo is an exterior impression or mold. Some of the shell may be present on the right side of the photo. Williams, Henry Shaler (1913). "New species of Silurian fossils from the Edmunds and Pembroke Formations of Washington County, Maine." Proceedings U.S. National Museum, 45, 319-358. https://repository.si.edu/bitstream/handle/10088/14399/1/USNMP-45_1985_1913.pdf Maine Geological Survey (2009). Virtual Tour of Maine's Fossils. https://digitalmaine.com/cgi/viewcontent.cgi?article=1575&context=mgs_publications
-
- 1
-
-
- actinopteria bella
- bivalve
- (and 6 more)
