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erose

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It was a beautiful day here in Austin and I decided to get a few quick hours in on some local Walnut Formation exposures. Lower Cretaceous. I think I found the largest Coenholectypus planatus I’ve ever seen. It is slightly crushed but would be a full 5 centimeters in diameter. My largest prior specimen was maybe 4cm. 

 

Tell/show me your largest of this species.

A4D9FDFA-9425-43FE-BF02-0F4EE0FBA997.jpeg

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Nice echie! 

 

Austin, Walnut formation, got it! Bucket list it goes. :D

Every single fossil you see is a miracle set in stone, and should be treated as such.

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I’ve seen more in the Kwa than Kgr, but larger in the Kgr.  Better avg condition in the Kwa; more compression in the Kgr. 

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

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Nice find! I wish I could find Echiniods in New York!

Dipleurawhisperer5.jpg

I like Trilo-butts and I cannot lie.

 

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I'm with Dave - I wish I could find echinoids up here in the Toronto area, too!!!  Very :envy:

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13 hours ago, Uncle Siphuncle said:

I’ve seen more in the Kwa than Kgr, but larger in the Kgr.  Better avg condition in the Kwa; more compression in the Kgr. 

I also have some big ones from the Kgr but still not a full 2 inches in diameter. In the Walnut at this local they come in all sizes and conditions.  

 

I have also never been able to sort out any of the other Walnut/Fredericksburg species from what I have collected over the years. I must have a hundred good specimens of all sizes from at least a dozen locals and I have laid them out and they form a perfect gray scale of small to large, round to pentagonal, round to pointed periproct, domed to pointed, etc. Nothing stood out as being distinctly Holectypus (Coenholectypus?) engerrandi or H. (C.) adkinsi. 

 

 

 

 

 

 

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20 minutes ago, erose said:

I also have some big ones from the Kgr but still not a full 2 inches in diameter. In the Walnut at this local they come in all sizes and conditions.  

 

I have also never been able to sort out any of the other Walnut/Fredericksburg species from what I have collected over the years. I must have a hundred good specimens of all sizes from at least a dozen locals and I have laid them out and they form a perfect gray scale of small to large, round to pentagonal, round to pointed periproct, domed to pointed, etc. Nothing stood out as being distinctly Holectypus (Coenholectypus?) engerrandi or H. (C.) adkinsi. 

 

 

 

 

 

 

I haven't dug into that too deep, but I would think an ovatus would be easy to sort out due to proportionally huge periproct.

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

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15 hours ago, erose said:

It was a beautiful day here in Austin and I decided to get a few quick hours in on some local Walnut Formation exposures. Lower Cretaceous. I think I found the largest Coenholectypus planatus I’ve ever seen. It is slightly crushed but would be a full 5 centimeters in diameter. My largest prior specimen was maybe 4cm. 

 

Tell/show me your largest of this species.

A4D9FDFA-9425-43FE-BF02-0F4EE0FBA997.jpeg

Wow! That IS a big'un! 

And, in awesome shape too. 

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Erich, you might check to see if there are different counts on the goniopores.  I seem to remember that might be a distinction between Holectypus and Coenholectypus.

The human mind has the ability to believe anything is true.  -  JJ

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John is indeed correct.  Coenholectypus has 5 and Holectypus has 4.

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

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2 hours ago, JohnJ said:

Erich, you might check to see if there are different counts on the goniopores.  I seem to remember that might be a distinction between Holectypus and Coenholectypus.

 

1 hour ago, Uncle Siphuncle said:

John is indeed correct.  Coenholectypus has 5 and Holectypus has 4.

Yes, I know. They all have five. Have yet to find a true Holectypus in the Walnut. 

 

Another group of Texas echinoids in need of sorting out IMHO.

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21 minutes ago, erose said:

 

Yes, I know. They all have five. Have yet to find a true Holectypus in the Walnut. 

 

Another group of Texas echinoids in need of sorting out IMHO.

To be honest, I haven’t studied mine closely.  Aquisition mode now, study mode in retirement.

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

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I found these two Coenholectypus in a Walnut Clay borrow pit on a ranch about 35 miles east of Abilene along the Callahan Divide in the Spring Gap area. The larger one is 5 cm across and 2.5 cm tall.  The smaller one is 3.5 cm wide and 1.5 cm tall.  Neither are perfect, but I'm happy with them nonetheless.  

Coenh1.JPG

Coenhol2.JPG

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A couple of days later I went to a smaller borrow pit (40' x 50'), still in the Walnut Clay, next to the road outside the fence of another ranch less than a quarter mile down the road and found this one, which I assume, since it has perforated tubercles, is a Tetragramma sp.  It is 6 cm across and 2.5 cm tall.  A chunk out of the side, some cracks in the test and not completely prepped, so not very pretty I'm afraid, but as in the others, I'm happy with my find.  I'm waiting for the day...somewhere in the next 25 years or so..lol!...when I can purchase an air abrasion pen and compressor and do it right and coax it gently out of what's left of the matrix. I sure didn't want to try and do it manually with picks, etc., fearing I'd damage it further.  So, That one small area of the Callahan Divide had some rather large specimens. Everything else I've found up and down the Divide in Callahan County has been just average in size. 

Tetragramma02.JPG

Tetragramma01.JPG

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Nice echs! That is a big one for sure. The Tetragramma sp. is also a great find. I would love to get up that way and collect in the Walnut where the mix is a bit different. 

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Nice echinoids, people! :)

I love the preservation on these. 

Thanks for sharing. 

Life's Good!

Tortoise Friend.

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6 hours ago, erose said:

Nice echs! That is a big one for sure. The Tetragramma sp. is also a great find. I would love to get up that way and collect in the Walnut where the mix is a bit different. 

Thanks! I've been trying to get time to talk to a couple of ranchers, but first I have to find their contact information. One of them is directly across the road from the original Spring Gap location in Callahan County. I'm very certain that if we could get on that place it would be untouched. The people who own the original ranch location no longer allow anyone outside deer leasees on their properties.  The first time Mike and I visited that place it was untouched as well. Phymosomas, Heterasters, Selenias, Coenholectypus, Tylostomas everywhere you looked and you could fill a bag with stuff just sitting in one location. I know the other ranches would be the same. 

 

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4 hours ago, Tidgy's Dad said:

Nice echinoids, people! :)

I love the preservation on these. 

Thanks for sharing. 

Thanks!  I had forgotten I had some fairly nice specimens. I'm being surprised here and there as I go back through 6 years of stuff. 

 

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