Duck Creek Formation fossil ID

[KimTexan]

I went fossil hunting Sunday in the Duck Creek Formation with my daughter. I found 3 small ammonites, numerous echinoids. There were also Inoceramus clams, large burrows and this things. I have no idea what this is. My impressionable mind wants to think it is part of a lobster since I saw the large burrows, but I’m pretty sure that isn’t likely. Since it is only a fragment it may not be identifiable as to belonging to any critter. 

It is about 3 inches long by 2.5 inches wide.

Pic 1 top view.

#2 end one

#3 end 2

#4 Side view

#5 bottom view. Pretty nondescript.

[Mike from North Queensland]

coprolite ??

 

Mike

[Heteromorph]

The lines at first made me think nautilus, but they are not straight enough. I have no idea! Maybe @BobWill or @Fruitbat could help. I know that Bob Will hunts in the Duck Creek Formation often.

[smt126]

i am thinking a poorly preserved nautiloid fragment

[KimTexan]

It doesn’t have a nautiloid feel or look to it in person. I have maybe 6-8 nautili that I have found, so I don’t think it’s nautiloid, but I could be wrong.  

[BobWill]

I don't think any amount of distortion could have turned a nautiloid into that thing I probably would have picked it up for a closer look but I don't think I would have brought it home. It's certainly odd looking but I don't see any symmetry or pattern. Sometimes that means it's a rudist clam according to the folks who know how to recognize those odd-balls but I have no solid experienced with them and don't know that they occur in the Duck Creek anyway.

[Heteromorph]

After Bob Will’s comment, my vote is for a geological piece that is suggestive of a fossil. 

[Herb]

my guess is part of an oyster shell

[GeschWhat]

From the top it looks like it could be an amphipolar coprolite, but the end doesn't look right. Any chance you could scrape the chalk from the other end to see if there is a spiral pattern?

[KimTexan]

2 hours ago, Herb said:

my guess is part of an oyster shell

I can see where it might appear to be part of an oyster shell. I have some giant Exogyra that have the similarity I believe you are thinking of, but I don’t believe it is that. All oysters in this area have their shells preserved and they are very hard. This is chalky in nature. Also the oysters of that size are not found in this formation that I know of. 

It really does have the shape of a lobster tail end and it curves and tapers like it too.

 

47 minutes ago, GeschWhat said:

Any chance you could scrape the chalk from the other end to see if there is a spiral pattern?

Would that be end 2 you refer to or end 1?

End 1 is covered in a material that resembles clam shell and is quite hard. End 2 is chalky. I can try to scrape end 2 away and send pics tomorrow.

[doushantuo]

 

galtsoff:

 

 

 

 

 

[doushantuo]

chalky deposits,separated by "subnacreous" layers(terminology of Ranson) 

 

 

[GeschWhat]

10 hours ago, KimTexan said:

End 1 is covered in a material that resembles clam shell and is quite hard. End 2 is chalky. I can try to scrape end 2 away and send pics tomorrow.

I was thinking end 2 

[KimTexan]

I certainly tried to scrape off the end, but it is pretty hard rock.

it is not very distinct in the pic, but there are definitely rolling layers. There was a swirl in the center that was more noticeable before I scraped some of the surface off. I initially thought it was the imprint of a small ammonite, but determined that wasn’t the case. After scraping though I can see more layers especially on the bottom right that roll or wrap up and around the right.

#5

I doubt this is any help, but I scraped the end of one of the tube shapes coming off of the side. I can’t see any of the rolls, swirls or folds that are seen in the other tube shapes. Maybe the critter was having a bout of the runs and the stool wasn’t formed. LOL However, note the tube structure on the top left. It has folds or a touch of swirls. See another pic below this one.

#6

Part of the bottom left of this tube has broken off. It does appear like it had a bit of swirl or roll to it.

#7

 

In picture #2 above of end 1 it looks like the layers are folds, mostly connected on the ends or sides that were compressed or squished like Golgie apparatus (if you know what those look like. I work with human cells.) somewhere along the line before fossilization.

All that said, my imagination could be getting the best of me and I have no clue what shark poo looks like. If it is shark. Shark teeth have been found in the area.

[GeschWhat]

Shark/spiral poo can vary a lot. If it is a spiral coprolite, it's the largest one I've seen from Texas. Does it have good stickage? Here are some from the Eagle Ford Formation (sorry no scale) and a group from the Ozan Formation (North Sulphur River) in Texas. 

[KimTexan]

I’d say it most likely resembles those in the 2nd shot in blue, especially the lower 2.

Regarding stickage, I’d say it has reasonable stickage, but considering that I just scraped off the surface and thoroughly washed it, I imagine it is considerably less sticky that it initially may have been.

Thanks for the pics, your comments and thoughts.

I tend to believe it is probably a coprolite. I think it may be my first.

Regarding size, some of the ammonite fauna in the area are quite large. From the ammonite fragments I saw near this item, they could easily be 20 inches in diameter or more.

Here is half of one I picked up from the same site on a prior visit.

I’m sure as I hunt the area I’ll find better ones.

I did find these, but they are much smaller (4-5 inches) and need cleaning up.

[GeschWhat]

Nice! Just out of curiosity, are the ammonites sticky when wet as well? Just curious, since I am not familiar with this formation. If the stickage is the same, it may not be a coprolite. I'd be interested to know what size/kind of shark/fish teeth you are finding. Based on the size of this (unless you have unusually small hands), a coprolite of that size would have to be a substantial fish. When you are out hunting, keep an eye out for long, thin coprolites or those that look like a pile of silly string. Ammonite poo is thought to look something like these from the Solnhofen Formation. I haven't seen anything like these outside of this formation, but it could happen . 

[KimTexan]

The small ammonites are not sticky. I thought they would be, because they look like the same kind of rock. Curious.

I don’t believe I have seen ammonite feces before. I will keep an eye out for it.

 

There are these long stringy things people have told me are worms. They don’t look segmented or sausage like though, but they are always wrapped up. I have always thought it was strange that you rarely if ever see them laid out straight. It is like finding earthworms always coiled. You don’t find them coiled. So I have wondered if they weren’t all worms, maybe some are poo.

[GeschWhat]

There is a good chance that the worm things are coprolites. Whether or not they are from cephalopods or other invertebrates I could not tell you. The Solnhofen coprolites I posted are known as Lumbricaria intestinum, which comes from the Latin term lumbricus, meaning "earthworm."   It got its name because they were originally thought to be worms. Unlike fish poo (which is primarily made up of calcium phosphate), Lumbricaria is primarily comprised of calcite. Some even have bits of floating crinoids (thought to be a an ammonite treat). The other day I came across some photos of sea cucumber feces which resembled some of the Solnhofen specimens in my collection. So yesterday I was looking at some NOAA photos and came across some that were absolutely amazing. Some are HERE and HERE and HERE. Probably TMI  , but when I see coprolites, I don't see poop. I envision the critters that may have produced it and the animals they consume.  Anyway, if you come across some of the coiled worm/coprolite fossils, please post them! Aside from the Solnhofen examples, I don't think there is much info out there about this type of coprolite.

[KimTexan]

I work in a clinical field. I’m not sure I know what TMI is anymore. I hear all kinds of stuff. Talking poo is pretty tame stuff.

 

“Dung expressions” LOL That was in the 3rd link. It made me laugh. That acorn worm is beautiful. I never thought I’d say that about a worm.

 

I have collected a number of the worm samples. Also, I think one of my first few posts for a clam ID had 2 kinds of worm looking things on the shell. One clearly looked like a kind of annelid, the other I had no idea. Maybe I can come up with a pic of it.

[KimTexan]

@GeschWhat

Here you go. Here is a pick of the worms. I’ve got numerous specimens of them besides this, but haven’t taken any pics of those. There is a big fat segmented annelid looking worm, then there is this tiny one on the top center on the edge of the clam shell.

Here is a closer pic of it. Every one I have ever seen is always looped or folded like that. If it was really a worm wouldn’t you expect to see them stretched out at least occasionally like the annelid or even the acorn worm in your link? So I tend to believe many are probably a form of feces.

I wonder what oyster, clam and echinoid poo looks like. Where I have seen the coils is where I have found a lot of oysters and echinoids. One site I visited about a month ago had a lot of these little coils. I’ll see if I can’t find some and take pics tomorrow.

That is one of the very first fossils I ever attempted to prep a few years ago. I did a horrendous job with leaving scratch marks. I had no clue what I was doing and no idea to look for other critters or anatomy. I think I accidentally removed part of the annelid without realizing it was even there.

[GeschWhat]

Are shells like this steinkerns or does the shell material itself fossilize? Forgive my ignorance when it comes to mollusk fossilization. I bet those are worm burrow casts or calcifications rather poo. Very cool though! That acorn worm really was beautiful. 

[Heteromorph]

1 hour ago, GeschWhat said:

Are shells like this steinkerns or does the shell material itself fossilize? Forgive my ignorance when it comes to mollusk fossilization. I bet those are worm burrow casts or calcifications rather poo. Very cool though! That acorn worm really was beautiful. 

The shells of bivalves fossilize. 

[KimTexan]

4 hours ago, Heteromorph said:

The shells of bivalves fossilize. 

I don’t know about all of them, I do have some that are steinkerns. I was thinking one of the ones I have that I’m certain is a steinkern was collected the same day and place as I collected this one. This one does not have the original shell and it would seem to be more steinkern like from the material, but I didn’t see the seam detail that is present in the steinkerns that I have. I am not sure how you could get worms to fossilize when you couldn’t get the shell to fossilize. There are worm burrows on this specimen and there also appears to be a worm coming out from inside the shell on the side.

I didn’t get around to finding the other examples of the worm that I have, but I did find one today on an echinoid. This is it. It’s still pretty dirty with rock on it. The red arrow is worn like structure.

Here is a close up. This is smaller than I usually see them.

[doushantuo]

 

 

 

doddJSRtexasdiagenes10.1.1.894.7566.pdf