Daryl McEwen

Unidentified Patterned Fossil

36 posts in this topic

but hang on. i mean, ya'll may well be onto the right answer. but what's weird about the specimen in question, if those are coprolites, is the uniformity of them. they all seem almost exactly the same length and diameter, and the ends are rounded just so. the comparative material posted has much greater variance between individual poops.

True, the comparative material posted has more variation in size. They are both examples of invertebrate coprolite masses, just clearly different species. Whatever made the coprolites in the original post must've made them in a very orderly fashion, like deer.

Share this post


Link to post
Share on other sites

Looking at my first picture a little closer... it looks like there is quite a bit of variation in my stool sample. Maybe slightly different critters? A couple small pieces seem to have the rounded edges like Daryl's specimen.

Now THESE look much more like callianassid coprolites. They have the rod shape with the broken ends perpendiclar to the long axis. The one on top is especially convincing because the lengthwise section shows the canals. Very nice examples!

Share this post


Link to post
Share on other sites

These are details undreamed of by me!

Thank you for lighting a candle in the dark room of my knowledge :)

Share this post


Link to post
Share on other sites

Thanks for the detailed information Carl. Interestingly, one of my pieces has some chitinous material attached to the coprolite/matrix mass. Its just a small patch, way too small for me to make an ID from, but I suppose it could be associated. Also I was going to comment on the phosphate preservation of the original specimen not jiving with a burrow (at least in my limited amateur experience) but then I remembered I just found this piece which sure looks like a phosphatic burrow to me. What do you think?

.5" wide

post-382-12591137597966_thumb.jpg

post-382-12591137677962_thumb.jpg

associated?

post-382-12591137831592_thumb.jpg

Edited by toothpuller

Share this post


Link to post
Share on other sites

Ophiomorpha are interesting in that it reflects as much about the sediment as the critter. At Big Brook you can go upstream and see another type of burrow called Thallianasoids (SP?) that is also made by Callianasid shrimp. But those are smooth sided. The sediment didn't need reinforcing with agglutinated pellets. In a few formations here in Texas we find a burrow called Spongeliomorpha which clearly shows longitudinal scratch marks where the critter dug through the sediment. These are also believed to be made by Callianasids.

Carl, you still in NYC? Send me a PM e-mail.

Share this post


Link to post
Share on other sites

Thanks for the detailed information Carl. Interestingly, one of my pieces has some chitinous material attached to the coprolite/matrix mass. Its just a small patch, way too small for me to make an ID from, but I suppose it could be associated. Also I was going to comment on the phosphate preservation of the original specimen not jiving with a burrow (at least in my limited amateur experience) but then I remembered I just found this piece which sure looks like a phosphatic burrow to me. What do you think?

.5" wide

post-382-12591137597966_thumb.jpg

post-382-12591137677962_thumb.jpg

associated?

post-382-12591137831592_thumb.jpg

I realized after writing that that saying they're never phosphatic was probably too strong a wording. As any of us fossil dweebs knows, practically anything is possible in the fossil record. I do think that the first and second pictures just posted are of a burrow, and, indeed, it looks fairly phosphatic.

Edited by Carl

Share this post


Link to post
Share on other sites

Ophiomorpha are interesting in that it reflects as much about the sediment as the critter. At Big Brook you can go upstream and see another type of burrow called Thallianasoids (SP?) that is also made by Callianasid shrimp. But those are smooth sided. The sediment didn't need reinforcing with agglutinated pellets. In a few formations here in Texas we find a burrow called Spongeliomorpha which clearly shows longitudinal scratch marks where the critter dug through the sediment. These are also believed to be made by Callianasids.

Carl, you still in NYC? Send me a PM e-mail.

Doc! I don't have your current email. You know how to find me, right? Same place.

Share this post


Link to post
Share on other sites

Don, you could check the fossil against the description of Halyminites

major in the Horace Richards 1958 monograph (Part I, Page 42, Plate

9). It's a form taxon for burrows, and your specimen generally

resembles the ones illustrated, although it is small and the markings

somewhat differently arranged. I've seen a number of them over the

years, but they are not so common as the text seems to indicate.

From Dave Parris

Share this post


Link to post
Share on other sites

Here's my example from Monmouth County, NJ:

post-1782-12597174469923_thumb.jpg

Share this post


Link to post
Share on other sites

Now THAT'S a spot on Ophiomorpha burrow (once called Halymenites)!

Share this post


Link to post
Share on other sites

Or is a type of Ophiomorpha sp.,or is a nodule of ematite mineral?

Share this post


Link to post
Share on other sites

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 account

Sign in

Already have an account? Sign in here.


Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.