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KimTexan

Texas Heteromorph ID

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Darktooth

Nice find Kim. Sorry I can't help with ID.

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DPS Ammonite

Is it from Rayzor Ranch area?

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KimTexan
Just now, DPS Ammonite said:

Is it from Rayzor Ranch area?

I have heard people mention Razor Ranch, but I don’t know where that is. This was from an area under construction off of 35 in Denton.

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KimTexan

I just went and looked it up. I think that may be the area, just north of UNT.

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KimTexan
11 minutes ago, Darktooth said:

Nice find Kim. Sorry I can't help with ID.

From the looks of it, it may have been maybe 4-5 inches originally.

It may have looked something like this, but probably tighter coils and more straight I believe.

I found fragments of these there too, but nothing so whole as this from another Grayson Formation spit I hunt.

1C7FBE9D-FBEC-47AA-BABC-1784579C096B.thumb.jpeg.80b7f5df60c5cc15ef652376a31ae45b.jpeg

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Innocentx

Very cool!

 

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Darktooth

Are you going to try to prep it?

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BobWill

Yes we find Mariella at Razor Ranch. Some are quite large. There are also some nice Cymatoceras nautiloids at the site. Also check the drainage ditch on the other side of 380 from the main site, past the Cracker Barrel. It's one of the rare places in the area where you find brachiopods, I believe they are Waconella and you can see the contact with some Main Street Formation there.

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KimTexan

 

 

1 hour ago, BobWill said:

Yes we find Mariella at Razor Ranch. Some are quite large. There are also some nice Cymatoceras nautiloids at the site. Also check the drainage ditch on the other side of 380 from the main site, past the Cracker Barrel. It's one of the rare places in the area where you find brachiopods, I believe they are Waconella and you can see the contact with some Main Street Formation there.

Thanks for the tip on the Main Street. I have never hunted it before. So I don’t even know what is in it.

 

Bob, I don’t believe this specimen is a Mariella brazoensis though. I have dozens and dozens of Mariellas or fragments of them. There are fewer tubercles and the tubercles are shaped differently than 

Mariella brazoensis.

 

I did find Mariellas there, but this is not like the others. So, either it is a different species or it is another genus, such as Turrilites.

Are Turrilites or other species of Mariellas found there?

 

So exactly where do you hunt there? I was in a field north of the Cinemark and a bit to the west of it. It might have been a Cheddars too.

I found a number of Texigryphea roemeri with both valves.

33E617ED-0332-4397-BE27-BB3B87F0E331.thumb.jpeg.f0b878058fd8a56ad44fdbb1fb18c5e4.jpegI found many Ilymotogyra arietina.  I am curious, are there 2 species or is the ornamentation just worn off on many. See the lines on the few on the left?

0876707E-3A4B-4790-B490-401C0407E158.thumb.jpeg.5b672b17be827b5e3099673f730d1a05.jpeg

I found the biggest ones I have ever found before there. They’re maybe 3-4 cm I think.

The 2 rows of 8 or 9 are the average size minus the white one. I found more than these though.

3346DBDD-D1F2-45F1-B47E-5225249D15DC.thumb.jpeg.66d42bcbacb6e0fd40b52c707d083e07.jpeg

 

I also found a few gastropods and clams among other stuff.

I think the one on the left is an Anchura. I had not found one in the Grayson before. I found one in the Goodland.

Do you know if the other is a Gyrodes? I do t think I have found one of this variety before. It’s maybe a little over an inch wide.

608D78F0-9D38-40DC-98BC-8CE13006B6F9.thumb.jpeg.e467f626e280d03eee7e0b107d3a2c8f.jpeg

 

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DPS Ammonite
2 hours ago, KimTexan said:

 

 

Thanks for the tip on the Main Street. I have never hunted it before. So I don’t even know what is in it.

 

Bob, I don’t believe this specimen is a Mariella brazoensis though. I have dozens and dozens of Mariellas or fragments of them. There are fewer tubercles and the tubercles are shaped differently than 

Mariella brazoensis.

 

I did find Mariellas there, but this is not like the others. So, either it is a different species or it is another genus, such as Turrilites.

Are Turrilites or other species of Mariellas found there?

 

So exactly where do you hunt there? I was in a field north of the Cinemark and a bit to the west of it. It might have been a Cheddars too.

I found a number of Texigryphea roemeri with both valves.

33E617ED-0332-4397-BE27-BB3B87F0E331.thumb.jpeg.f0b878058fd8a56ad44fdbb1fb18c5e4.jpegI found many Ilymotogyra arietina.  I am curious, are there 2 species or is the ornamentation just worn off on many. See the lines on the few on the left?

0876707E-3A4B-4790-B490-401C0407E158.thumb.jpeg.5b672b17be827b5e3099673f730d1a05.jpeg

 

Ilmatogyra arietina have varying amounts of the ribbed ornamentation on the oldest part of the shell. The heavily ribbed small ones are just immature Illmatogyra. Some have suggested that the ribbing comes from a possible ancestor (Exogyra  plexa). See this document from "The Evolution of Exogyra plexa" by Bernard Yurke:

http://homepage.physics.uiowa.edu/~cnewsom/fossils/Oysters/ilymatogyra/Exogyra-plexa.html

EDIT: added oyster reference. @KimTexan

 

Oysters with both valves which are common in the Grayson Fm. are probably created when a storm, slide, turbidite flow, or tsunami bury the live shells.

 

 

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KimTexan
2 minutes ago, DPS Ammonite said:

Ilmatogyra arietina have varying amounts of the ribbed ornamentation on the oldest part of the shell. The heavily ribbed small ones are just immature Illmatogyra. Oysters with both valves which are common in the Grayson Fm. are probably created when a storm, slide, turbidite flow, or tsunami bury the live shells.

Do you know the ID of the heteromorph or the gastropod on the right John?

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BobWill

So many questions, so little oregano...

You may not have enough of the heteromorph to tell. Could the different look be due to more wear than the other ones you have? Without enough whorls to measure the apical angle or complete flanks to count rows of tubercles I don't know how you would tell.

I don't think the oysters with longitudinal striations are Ilymatogyra. There are so many different oysters I have trouble with them though. Edit: John may have just answered that Q. I see the right valves alone sometimes but I guess I've never seen the mature left valve.

There's a Cinemark there now? They are building stuff so fast I can't keep track. It seems like every time I go they're plowing under a new section. I never know where It will be safe to hunt. We should make the most of this site before it's all concrete and Cheddars.

I know Gyrodes can be found in the Upper Cretaceous but I don't know about the lower formations. It certainly looks similar.

The Main Street Formation is below the Grayson. I think I've only seen it at the lowest part of the drainage ditch over beside Sam"s. I have trouble telling but I'm told it has more limestone than marl while The Grayson is more marl with occasional limestone at the top.

The brachiopods I mentioned are only at the west end of the ditch.

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DPS Ammonite

I am not sure what the gastropods are. Gyrodes is a good guess and seems to be a common name for the similiar steinkerns without diagnostic exterior ornamentation throughout Northern Texas.

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BobWill

What's showing of your high-spired gastropod does look like Anchura but I don't know if it's known from the Grayson or not. It looks like it is partly internal mold and part external cast but the bottom is missing. I did find this snail there showing similar ornamentation at the top of the whorl but slightly different at the bottom, more like Drapanochilus but I don't know if they are supposed to be there or not either. 5ba91cdc6a166_Picture066.jpg.9ac12b151af8537441cd69383e50c4e1.jpg

 

 

Edit: I'm having a chat with John to see if we can tell why the two oysters seem so different.

 

 

 

Also here is the right valve of Ilymatogyra so you know what to look for.

5ba91d2bdf678_Picture060.jpg.a6e0b2914e73e267c50a97f46cca6bc6.jpg5ba91d361b6c4_Picture059.jpg.236f82ad86df946fe97cebabe031951b.jpg5ba91d40890d4_Picture062.jpg.14a7006e5774e4607ab645229137ccf9.jpg

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KimTexan
On 9/24/2018 at 12:22 PM, BobWill said:

What's showing of your high-spired gastropod does look like Anchura but I don't know if it's known from the Grayson or not. It looks like it is partly internal mold and part external cast but the bottom is missing. I did find this snail there showing similar ornamentation at the top of the whorl but slightly different at the bottom, more like Drapanochilus but I don't know if they are supposed to be there or not either. 

 

 

Edit: I'm having a chat with John to see if we can tell why the two oysters seem so different.

 

Anymore info on the oysters if they’re the same or not?

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BobWill
1 hour ago, KimTexan said:

Anymore info on the oysters if they’re the same or not?

Sorry, I forgot to update the thread. John (DPS Ammonite) thinks they're the same, just showing extreme intra-species variation, or whatever you would call that. I don't have any resources to challenge that. Maybe someone else can confirm it for us.

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PFOOLEY

@LanceH has some examples of Turrilites sp. from the Grayson on his website, North Texas Fossils...might be worth a gander.

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DPS Ammonite

I think that your oysters are variations on the same species. My recollection of Illmatogyra arietina collected from the Mainstreet and Grayson Formations is that there was varying amounts of ribbing. Some of them had many spirals at the oldest part of the shell; some had none because the shell had a large attachment scar.I remember seeing forms that had ribs and large attachment scars in the Grayson that looked like the pictures 2a, 2b and 2c in figure 7 below. 

 

It is not a stretch that the forms found in the Mainstreet could also be in the Grayson since they are close in age. Also, it is possible that some of the Mainstreet forms could be reworked into the Grayson.

 

See figure 7 in "The Evolution of Exogrya plexa" by Bernard Yurke.

http://homepage.physics.uiowa.edu/~cnewsom/fossils/Oysters/ilymatogyra/Exogyra-plexa.html

 

 
Figure 7. Lower view of lower valves. 1a and 1b are I. arietina from the Grayson Formation. 2a-2c are I. arietina from the Main Street Formation. 3a-3d are E. plexa from the Duck Creek Formation. 4a-4d are E. plexa from the Kiamichi Formation. 5a-5c are E. plexa from the Goodland Formation. All images are set to the same linear scale for easy size comparison. The height of the image 1a is 2.28 cm.

IMG_0594.JPG

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KimTexan

Thank you for responding. That is helpful.

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PFOOLEY

HERE is a similar query. :)

 

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KimTexan

I have found many, many Mariella fragments. In the hundreds I’d guess. Only 2 species I believe. But before Labor Day I went hunting in the Grayson in Hurst. While extracting a Graysonites I came across many more Mariella fragments. But then I came across a fragment which was strikingly different than any other I had ever seen. The tubercles were very sharp and pointy and the curve of the whorl was very different too. It was a heteromorph, but not like any other I have seen. 

I don’t have much proof to go off of, but I suspect it may be a Turrilites. I think I accidentally packed it away a couple weeks ago and I’m not very motivated to go dig it out.

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KimTexan
33 minutes ago, PFOOLEY said:

Not sure how much help this will be on this topic, but I thought this was a cool reference...

 

Lower Cenomanian and Late Albian (Cretaceous) Ammonites, Especially Lyelliceridae, of Texas and Mexico

 

...and right up your alley.

Thank you!!! I don’t actually have that one. That is worth printing out.

I try to keep track of everyone’s first names, but I don’t remember yours. May I ask your name? Or is that impolite to do here?

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KimTexan
36 minutes ago, PFOOLEY said:

Not sure how much help this will be on this topic, but I thought this was a cool reference...

 

Lower Cenomanian and Late Albian (Cretaceous) Ammonites, Especially Lyelliceridae, of Texas and Mexico

 

...and right up your alley.

I have certainly enjoyed your ammonites. I’ve seen a number from our Eagle Ford that remarkable ones you find at times.

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