Duck Creek Formation fossil ID

[JohnJ]

4 hours ago, KimTexan said:

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.

Kim, do a search on the Forum for "serpulid worms" and you will see more examples of these squiggly calcareous tube builders. For starters, check Here. More cool finds.

[Heteromorph]

8 hours ago, KimTexan said:

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.

I have found many inoceramids from the Austin Chalk that are just steinkerns, but that is because the calcite shells always want to separate from the steinkern. I am not really sure why, but at least that is how it is in the Austin Chalk. I would assume that fossils in the Duck Creek Formation were lithified in a similar manner. 

 

By the way, I am curious if you know the species of the echinoid with the worm on it. 

[doushantuo]

Dysoxia favours carbonate mineral dissolution.The Austin Chalk might have been (intermittently)an-/dysoxic

(low bottom water oxygenation)

Size might be affected by these adverse conditions,as well

[Heteromorph]

6 minutes ago, doushantuo said:

Dysoxia favours carbonate mineral dissolution.The Austin Chalk might have been (intermittently)an-/dysoxic

(low bottom water oxygenation)

Thanks! I didn’t know that. 

[KimTexan]

40 minutes ago, Heteromorph said:

I have found many inoceramids from the Austin Chalk that are just steinkerns, but that is because the calcite shells always want to separate from the steinkern. I am not really sure why, but at least that is how it is in the Austin Chalk. I would assume that fossils in the Duck Creek Formation were lithified in a similar manner. 

 

By the way, I am curious if you know the species of the echinoid with the worm on it. 

No I haven’t got it cleaned up yet. I haven’t uncovered the periproct yet. I had initially thought it was another Coenholectypus castilloi when I first picked it up, but when I got it home I realized it must be something different or the species changes as it gets bigger or something. I have found numerous castilloi in this location, but this one is much bigger and looks different. It may be a planatus species with the apical disk in place. 

Do you happen to know what it is?

Edited December 22, 2017 by KimTexan
Misspelled periproct

[KimTexan]

I know I have to take my time removing the matrix from these things because a couple weeks ago I destroyed a beautiful one by being to hasty with trying to get the matrix off. 

Prior to finding this site the vast majority of my echinoids have been irregular echinoids. The test on the irregulars that I have found are nearly indestructible. They are very hard and don’t chip or break if intact. Regular urchins are a completely different matter.

Of note I found 5 echinoids in about a 1.5 foot area of at least 2 genus and 3 species. This one is about 65 mm wide. One found maybe 3 cm away looks more like castilloi, but again I still need to uncover the periproct to confirm. The matrix is marl so it is a bit hard and I need to be delicate.

Do you know of a quick and easy way to remove marl? I’m always look for some magical matrix removal that I don’t think exists. I found an amazing and large conglomerate with 4 good size Mariella brazoensis in it and I think a small nautilus among other stuff. I packed it out of where I found it, but it sure was heavy.

[Heteromorph]

1 hour ago, KimTexan said:

No I haven’t got it cleaned up yet. I haven’t uncovered the periproct yet. I had initially thought it was another Coenholectypus castilloi when I first picked it up, but when I got it home I realized it must be something different or the species changes as it gets bigger or something. I have found numerous castilloi in this location, but this one is much bigger and looks different. It may be a planatus species with the apical disk in place. 

Do you happen to know what it is?

I don't know for sure, but from looking at Bill's book perhaps it is Globator inaudita? It is reported from the Denton Formation. That is just my guess, so take it with a grain of salt. Coenholectypus planatus does very much resemble your specimen, but I see that it is only reported from the Glen Rose formation. 

1 hour ago, KimTexan said:

I know I have to take my time removing the matrix from these things because a couple weeks ago I destroyed a beautiful one by being to hasty with trying to get the matrix off. 

Prior to finding this site the vast majority of my echinoids have been irregular echinoids. The test on the irregulars that I have found are nearly indestructible. They are very hard and don’t chip or break if intact. Regular urchins are a completely different matter.

Of note I found 5 echinoids in about a 1.5 foot area of at least 2 genus and 3 species. This one is about 65 mm wide. One found maybe 3 cm away looks more like castilloi, but again I still need to uncover the periproct to confirm. The matrix is marl so it is a bit hard and I need to be delicate.

Do you know of a quick and easy way to remove marl? I’m always look for some magical matrix removal that I don’t think exists. I found an amazing and large conglomerate with 4 good size Mariella brazoensis in it and I think a small nautilus among other stuff. I packed it out of where I found it, but it sure was heavy.

Sounds like a great haul!

 

I have no experience prepping echinoids out of marl, but perhaps others could help. 

[KimTexan]

This was from the Grayson marl. There are Waconella wacoensis and Llymotogyra oysters. I think they may be index fossils for the formation.

You can’t tell it from the pics, but it is actually kind of conical on top. So I tend to think it is a Coenholectypus of some sort. I’ll post it on here once I get it cleaned up. I think I found 5-6 of them all in various sizes from about 22-65 mm. The 65 mm may be bigger once I get the matrix off. The matrix is blocking accurate measurement. I’m not sure when I’ll get around to cleaning them though. I have company coming tonight through 12/26 and I’m on call tonight through 12/26 AM and work the rest of the week.

You're right about the Coenholectypus planatus   it does seem to be in a very different region. I am a novice at this and don’t know where what is found yet. I’ll get there. I still haven’t ID’d the majority of my collection I have collected over the years.

[Uncle Siphuncle]

ID is easiest when you can see the peristome and periproct clearly.

[Coco]

Hi,

 

If you have some marl on the sea urchin, try to put just a little hydrogen peroxide diluted in places to be cleaned with a brush and have a look on it, don't soak it because that could make it burst. Then rince well.

 

Coco

[KimTexan]

On 12/22/2017 at 2:51 PM, Uncle Siphuncle said:

ID is easiest when you can see the peristome and periproct clearly.

I do understand that especially for this genus. The original post was about something else, then it diverted to serpulid worms and I posted the unprepared urchin to show the worm on the surface.

My hunch is that they are the Coenholectypus castilloi. I have found a few of them there before.

 

On 12/23/2017 at 3:55 AM, Coco said:

Hi,

 

If you have some marl on the sea urchin, try to put just a little hydrogen peroxide diluted in places to be cleaned with a brush and have a look on it, don't soak it because that could make it burst. Then rince well.

 

Coco

Thank you I will try that. Thanks for the heads up about exploding urchins too.

It is more than just marl though. There are a couple oysters attached to the bottom coveting the periosteum. That takes a lot of work to remove.