Daryl McEwen

Unidentified Patterned Fossil

36 posts in this topic

Here's another unidentified fossil I found recently. Ozzyrules said that it could be a hybodont spine fragment but I'm not so sure. I actually found this with a hybodont spine fragment close by during the same dig but the pattern is quite different on this one. Just wanted another opinion if possible.

16440_212482011140_749236140_4493492_1320527_n.jpg

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Perhaps a crustacean egg nest?.

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fusulinids?

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Bacterial slide from the movie "Outbreak?"

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Fossil Poop? :wacko:

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Late Cretaceous marine, right? It's a mass of tiny invertebrate coprolites. Can say which spineless thing it was though.

Edited by Carl

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Late Cretaceous marine, right? It's a mass of tiny invertebrate coprolites. Can say which spineless thing it was though.

yes, late cretaceous marine is the most likely origin. have you ever seen anything like this before? Invertebrate coprolite mass does seem a likely candidate but I'm not 100% sold just yet, not without another photo for comparison. Its not a very impressive fossil but the mystery of it is interesting. Thanks for all input.

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fusulinids?

Second the motion

Brent Ashcraft

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Hi there, i'm new to the blog, and just checking out the un'id's. You have a burrow that is lined with fecal pelets. Most likely a pelecypod or perhaps crab.

Pretty cool.

dinodigger

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i don't disagree with that concept. throwing out the fusulinids thing was a bit of a stretch due to the rounded ends not looking exactly right and the nature of the material. looks more organic-phosphatic or something and less like calcareous material. i did consider that whatever it was looked kinda like a tumbled section of a burrow infilling. some of those things look pretty different, like these two...

post-488-12587616838856_thumb.jpg

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What's it taste like? :D

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I like the idea of it being a burrow cast with "leavings". I thought it looked a lot like rod-shaped bacteria or active baking yeast piled together, but I couldn't figure out the stem shape with the patterns on a curved surface.

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yes, late cretaceous marine is the most likely origin. have you ever seen anything like this before? Invertebrate coprolite mass does seem a likely candidate but I'm not 100% sold just yet, not without another photo for comparison. Its not a very impressive fossil but the mystery of it is interesting. Thanks for all input.

If I found that at one of my sites, I'd have no doubt at all that it was a mass of invertebrate coprolites. Even cut and polished, they normally have no internal structure, which would rule out fusilinids and such. But those that do have internal structure often prove to be the coprolites of callianassid shrimp. But that's not likely here because they are usually preserved as rods with end faces perpendicular to the long axis rather than rounded as yours have.

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If I found that at one of my sites, I'd have no doubt at all that it was a mass of invertebrate coprolites. Even cut and polished, they normally have no internal structure, which would rule out fusilinids and such. But those that do have internal structure often prove to be the coprolites of callianassid shrimp. But that's not likely here because they are usually preserved as rods with end faces perpendicular to the long axis rather than rounded as yours have.

i have to ask the obvious question. why do the coprolites of "callianassid" shrimp have internal structure?

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Here's another unidentified fossil I found recently.

16440_212482011140_749236140_4493492_1320527_n.jpg

I just this moment received my copy of "Discovering Fossils" (from Miller's Fossils, and signed by both authors B) ), and on page 168 is a drawing that looks just like your fossil! It is identified as Ophiomorpha nodosa, the burrow of a ghost shrimp (Cretaceous to Pleistocene).

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I just this moment received my copy of "Discovering Fossils" (from Miller's Fossils, and signed by both authors B) ), and on page 168 is a drawing that looks just like your fossil! It is identified as Ophiomorpha nodosa, the burrow of a ghost shrimp (Cretaceous to Pleistocene).

Umm Auspex, illustrations can be deceiving :) , Cretaceous Ghost shrimp burrows are usually several inches in length. I've been viewing this for a while and I am stumped. I seriously doubt that this is a "mass of coprolites," but I still can't offer a knowledgable guess as to what it really is.

Discovering Fossils - best book about fossils I've ever written. :D

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I am thinking along the same lines as Carl. For reference, the largest piece is .75".

post-382-12590246712058_thumb.jpg

Edited by toothpuller

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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.

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Maybe it's a baby crab?

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Ok just to add fuel, here is what a classic Cretaceous Ophiomorpha nodosa ghost shrimp burrow from NJ looks like. It is about 21/2 inches in length and broken on both ends.

post-2027-12590271946963_thumb.jpg

Edited by Smilodon

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I don't have all the answers, but the fossil in question comes from an extremely reworked layer and this might be obscuring some original detail. The size and shape of the pellets does seem more akin to Ophiomorpha burrow linings in which callianassid shrimp are suspected of lining their burrows with agglutinated pelletoidal sediment for stability, but the specimen is much smaller than common Ophiomorpha burrows.

post-382-12590276866285_thumb.jpg

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.

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.

Edited by toothpuller

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Umm Auspex, illustrations can be deceiving :) , Cretaceous Ghost shrimp burrows are usually several inches in length. I've been viewing this for a while and I am stumped. I seriously doubt that this is a "mass of coprolites," but I still can't offer a knowledgable guess as to what it really is.

Discovering Fossils - best book about fossils I've ever written. :D

Holy snarge, you're Don Miller? Your guys' book was the first one I purchased before I really started getting into hunting. Its also the most well-rounded text on fossils I've been able to find to date. Thanks for all the great info!

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Holy snarge, you're Don Miller? Your guys' book was the first one I purchased before I really started getting into hunting. Its also the most well-rounded text on fossils I've been able to find to date. Thanks for all the great info!

Why than you, than you vurry much

(Doing my best online Elvis impression)

Seriously, Daryl, thank you. It's nice to GET an attaboy once in a while. :)

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i have to ask the obvious question. why do the coprolites of "callianassid" shrimp have internal structure?

Modern and fossil fecal pellets from ghost shrimp are easily identified by the bilaterally symmetrical arrangement of two groups of canals (a.k.a. haemorrhodilates) that run the length of the pellets parallel to the long axis. These canals derive from projections extending from the posterior margin of the rear gut that leave their mark on the still-fluid feces as it travels past them. These projections likely divert larger particles in the feces, which might irritate the tissues of the shrimp, away from the pellet edges. The pattern of canals is species-specific and aids ecologists studying modern ecosystems in identifying the pellet’s producers. These canal patterns are very obvious in the fossil forms as well.

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I just this moment received my copy of "Discovering Fossils" (from Miller's Fossils, and signed by both authors B) ), and on page 168 is a drawing that looks just like your fossil! It is identified as Ophiomorpha nodosa, the burrow of a ghost shrimp (Cretaceous to Pleistocene).

Ophiomorpha is much larger than this, never phosphatic in preservation, and the bumps are circular rather than elongated. The irony is that the same animal makes both structures!

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