Rockhopper Posted April 4, 2018 Share Posted April 4, 2018 I found this fossil associated with crinoid fragments, a fish spine, and corals. The location was a small canyon in the Cottonwood Mountains of Death Valley. Collecting is not allowed, so unfortunately I have only the one field photograph. Any ideas? It's small; length is about 1.5 cm, a little over half an inch. 1 Link to comment Share on other sites More sharing options...
izak_ Posted April 4, 2018 Share Posted April 4, 2018 Maybe a bryozoan or coral encrusted crinoid stem. Also do you have any pics of the fish spine? Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted April 4, 2018 Share Posted April 4, 2018 Looks like a fossil chiton to me. It's very beautiful! Oh, and hello, and a very warm welcome to TFF from Morocco! 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
abyssunder Posted April 4, 2018 Share Posted April 4, 2018 Chitons have eight segments. 2 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Rockhopper Posted April 4, 2018 Author Share Posted April 4, 2018 (edited) I was wondering if the grayish projections were secondary growths. Here's a picture of the fish spine. (edit: it's about 6 cm long, about 3 inches. Not a fish you'd keep for dinner, exactly.) Edited April 4, 2018 by Rockhopper 1 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted April 4, 2018 Share Posted April 4, 2018 33 minutes ago, abyssunder said: Chitons have eight segments. True. Okay a related early polyplacophoran? 2 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
GeschWhat Posted April 4, 2018 Share Posted April 4, 2018 Beautiful! Lori www.areallycrappystory.com/fossils www.facebook.com/fossilpoo Link to comment Share on other sites More sharing options...
DevonianDigger Posted April 4, 2018 Share Posted April 4, 2018 Whatever it is, it's quite cool! At least you'll always have the picture. Jay A. Wollin Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve Hamburg, New York, USA Link to comment Share on other sites More sharing options...
ynot Posted April 4, 2018 Share Posted April 4, 2018 2 hours ago, Tidgy's Dad said: True. Okay a related early polyplacophoran? Have to disagree with this. We are looking at a transverse cross section with an internal structure exposed. There is a smaller one that is a better cross section just below the main piece. I agree with an encrusting bryozoan on something (crinoid or cephalopod?). Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
TqB Posted April 4, 2018 Share Posted April 4, 2018 7 hours ago, Foozil said: Maybe a bryozoan or coral encrusted crinoid stem. Also do you have any pics of the fish spine? I agree, bryozoan on crinoid. Tarquin Link to comment Share on other sites More sharing options...
Rockhopper Posted April 4, 2018 Author Share Posted April 4, 2018 Nice ID, thanks all. And thanks for the welcome to the forum! -- Don Link to comment Share on other sites More sharing options...
Coco Posted April 7, 2018 Share Posted April 7, 2018 Not a chiton. Have a look on my signature, you can find some publications about recent polyplacophora. As Abyssunder said : chitons always have 8 plates. Coco ---------------------- OUTIL POUR MESURER VOS FOSSILES : ici Ma bibliothèque PDF 1 (Poissons et sélaciens récents & fossiles) : ici Ma bibliothèque PDF 2 (Animaux vivants - sans poissons ni sélaciens) : ici Mâchoires sélaciennes récentes : ici Hétérodontiques et sélaciens : ici Oeufs sélaciens récents : ici Otolithes de poissons récents ! ici Un Greg... Link to comment Share on other sites More sharing options...
Rockhopper Posted April 16, 2018 Author Share Posted April 16, 2018 I'm slightly embarrassed, as the segmented section in the original post pretty much exactly matches the crinoid segments found in other rocks at the site -- clearly a fragment of crinoid stem. I should have figured that out from the context. The grayish halo of other material may be badly weathered: wherever the other fossils included similar grayish mineral, the mineral appears to have weathered much faster than the rusty-brown matrix. Perhaps it's a carbonate, and particularly soluble. Given the degree of probable erosion, I wouldn't know a bryozoan from an encrusting coral. Or from bubblegum. In the image below, from the same site, you can see crinoid segments which have eroded preferentially, leaving in one case something that looks very much like vertebrae -- but which is really the cast of the inner canal of the criniod stem, I think, surrounded by the eroded mineral of the stem discs. To the right are a couple of stem segments that have mostly lost the gray mineral, leaving the inner canal surrounded by the radially-grooved inter-segment surfaces. At least, that's how I interpret it. Tricky stuff, these fossil tricks. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now