West Texas Cretaceous Brachiopod Question

[JamieLynn]

Howdy! So I was out in West Texas this last weekend trying to hunt down some new echinoids (will post those later!) but i came across some odd looking brachiopods.  I am 99 percent sure the formation was Buda (it's kind of hard to be certain as I am no geologist -but that  is what I pinpointed on the Texas Geological map, but I might have been at the wrong roadcut, too).  The other fossils I found there were Texigryphaea and Neithia texana.  I am familiar with the Brachiopod Kingena wacoensis in the Georgetown formation of Central Texas Cretacous. I wasn't sure if Kingena is found in the Buda formtion for one thing. A second thing, these look very different than Kingena. These have a "dip" in them more like Pennsylvanian brachiopod Composita.  All the other Kingena I have found are straight "lipped". 

 

Any help would be appreciated!

 

 

[ClearLake]

They do indeed look like Composita but that genus was extinct long before the Cretaceous (in fact the whole family Athyrididae went extinct at the end of the Permian). I am not familiar with a Cretaceous form that looks like that, but I don’t have my book with me to confirm that. FYI, the “dip” is called a sulcus and the corresponding hump is called a fold. Perhaps someone left this very common Pennsylvanian fossil at your outcrop?

[JamieLynn]

12 minutes ago, ClearLake said:

They do indeed look like Composita but that genus was extinct long before the Cretaceous (in fact the whole family Athyrididae went extinct at the end of the Permian). I am not familiar with a Cretaceous form that looks like that, but I don’t have my book with me to confirm that. FYI, the “dip” is called a sulcus and the corresponding hump is called a fold. Perhaps someone left this very common Pennsylvanian fossil at your outcrop?

 

Thanks for the vocabulary!  These were definitely not "left behind" as I had to chip most of them out of the limestone! They are definitely from that strata.

[Creek - Don]

Agreed, it's a Pennsylvanian Composita.  Dallas Paleontological Society has found same ones near Jacksboro Pennsylvanian site.    

 

 

[JamieLynn]

16 minutes ago, Creek - Don said:

Agreed, it's a Pennsylvanian Composita.  Dallas Paleontological Society has found same ones near Jacksboro Pennyslvanian site.    

 

 

 

well then about a thousand pennsylvanian brachiopods are all mixed in with Cretaceous fauna in limestone strata in West Texas. 

[Herb]

where did you find them

[JamieLynn]

In a roadcut on I-10 near the junction of I-10 and I-20 . I was looking for the Boracho /San Martine formation and there is a series of 5 roadcuts of San Martine, Buda and Boquillas. I was at the one I assumed was Buda.

 

 My Dad took pics of the strata and the layer with the brachiopods and grypheas. I will get that pic from him tomorrow. 

[JamieLynn]

Here is a pic of the other things I found at this roadcut 

 

[Creek - Don]

Nearest Permian formation between where that was found.  Not very far. 

[JamieLynn]

@Creek - Don   this is where it was found: 

[Creek - Don]

Right, you are about 20 miles east of Permian formation.  I think you've got Permian formation deposits mixed with Cretaceous deposits. 

[erose]

There are very few common brachiopods in the Cretaceous of Texas. BUT there are brachiopods and yours is certainly one of them. I’ll look thru my literature and see what I find.  
 

[JamieLynn]

@Creek - Don - while I suppose that is definitely possible, i"ve not heard of such a thing. I'd love to hear from some TFF members if they've found a situation like that. 

[JamieLynn]

This is the roadcut. They were in the layer about half way up 

[erose]

11 minutes ago, Creek - Don said:

Right, you are about 20 miles east of Permian formation.  I think you've got Permian formation deposits mixed with Cretaceous deposits. 

 

8 minutes ago, JamieLynn said:

@Creek - Don - while I suppose that is definitely possible, i"ve not heard of such a thing. I'd love to hear from some TFF members if they've found a situation like that. 

I trust Jamie if she says it comes from

the Cretaceous strata. There is some unusual geology out that way but I also don’t know of any Permian/Cretaceous intermingling in that area. 
 

There are plenty of undescribed fossils still in our Texas rocks. But i won’t be surprised if I find this somewhere in the literature. 

[erose]

Did a quick search of a few references. Nothing obvious showed up. This may be Kingena.  I would consider labeling it Kingena sp.  There is another Kingena species in the Glen Rose so there may be another species in the Buda. 

[DPS Ammonite]

Here is a French species Kingena elegans with a sulcus. You might want to send photos of the possible new species to local paleo departments. I know that DPS works with several. Any suggestions of local professionals that like Cretaceous fossils?

 

 

 

Edited August 5, 2020 by DPS Ammonite

[JamieLynn]

11 minutes ago, erose said:

Did a quick search of a few references. Nothing obvious showed up. This may be Kingena.  I would consider labeling it Kingena sp.  There is another Kingena species in the Glen Rose so there may be another species in the Buda. 

 

So there is a species in the Glen Rose? I had seen Kingina listed in the Handbook of Texas Fossils in the Glen Rose, but have never seen one. .

[ClearLake]

I might suggest, if you can, to do a little more cleaning of your specimens around the beak and/or pedical opening.  That may be fairly critical in getting a good ID. Did you find any specimens where you can see the interior of the valves?  Thanks

[grandpa]

Jamie,  as a fellow central Texan, I must say that I find your posts bring some of the most challenging and intriguing questions that I can relate to from my similar hunting experiences.  I love your posts.

 

Can't wait to see the solution to this one.

 

Keep finding things where they don't belong and bringing them to our attention.  I learn a lot from your posts.

[JamieLynn]

hahhahah!! Thank you @grandpa ! I know enough to know I don't know much.....:D 

@ClearLake - I did not find any that were open, or rather, I did not pick any up. I will clean them up and take a few close up pics. 

[JamieLynn]

4 hours ago, ClearLake said:

I might suggest, if you can, to do a little more cleaning of your specimens around the beak and/or pedical opening.  That may be fairly critical in getting a good ID. Did you find any specimens where you can see the interior of the valves?  Thanks

 

I did a little cleaning. Here is the best one. And the second picture is of a Kingena wacoensis from the Georgetown Formation in Central Texas for comparison

 

 

From Georgetown formation in Central Texas: 

 

[DPS Ammonite]

1 hour ago, JamieLynn said:

 

I did a little cleaning. Here is the best one. And the second picture is of a Kingena wacoensis from the Georgetown Formation in Central Texas for comparison

 

 

From Georgetown formation in Central Texas: 

 

I looked at multiple specimens of  Kingena and Composita to look for differences. I think that I found one, the shape of the brachial valve near the foremen. The shape of the part of the brachial valve nearest the foremen is broadly arching in Kingena. In Composita the shape is angular. See your marked up Kingena photo and a Composita from the Index Fossils of North America.

 

Yours are likely Kingena and not Composita.

[JamieLynn]

excellent eye for detail @DPS Ammonite . Thanks! 

[erose]

"Terabratalid"  brachiopods can be hard to ID to higher level without seeing internal structure. I think this is most likely a variation on Kingena wacoensis with a somewhat deeper sulcus. After looking at my specimens from the Georgetown Fm here in Austin some show a slight sulcus along the margin.

 

But as mentioned earlier there are other brachiopods in our Texas Cretaceous rocks. Whitney (1937) names three new species from the Glen Rose Formation. One of those is Kingena saffordi. A good friend and collector mentioned brachs could be found in Unit 3 of the Upper Member at one site. Sure enough I found a few, all generally scrappy. But I do have one small perfect one (sorry no pic of that yet) I now have specimens from two locations, both Unit 3.  Here are some photos.  I have yet to find any of the two species of Rhynchonella he erected.