Rudists of the Western Interior

[Opuntia]

Back in February of 2021, I found a rudist in the Cenomanian Paguate member of the Dakota Formation. I was fortunate to have this fossil published into the New Mexico fossil record. As an early budding amateur, I never thought this was possible. With the help of @PFOOLEY and Dr. Spencer G. Lucas, that dream came true, and I'm forever thankful. This rudist came from a limestone concretion the size of a basketball. Not an easy break. When it finally cracked this is what I saw:

 

It looked odd enough for me to keep and mention it later to Mike. 

 

Here is the paper: 

26-PAGUATEMEMBER.pdf

 

The museum assigned it to the genus, Durania. 

Being new to fossil collecting, I had no idea what a rudist was. So of course, I dove into research. This gave me a new appreciation for fossils, ancient life and the ancient environment. And it changed my approach in fossil collection. 

 

Rudists are uncommon in the Western Interior seaway. Only a handful have been found in New Mexico, most without documentation. 

 

This past Sunday, Mike and I returned to the Paguate member, fairly close to where I found Durania sp. Towards the end of the day, I cracked open a sandstone concretion. At first glance I thought it was petrified wood, as it is somewhat common in these parts. But to my surprise, there was another rudist in this concretion. Wow!!

With Mike's confirmation, we both agreed it was another rudist. 

Here it is: 

 

 

It is a bit difficult to bring out the fossil in photos as it is the exact same color as the sandstone. I'll take some better photos with my mirrorless camera soon. 

 

Now time for research.

I found a few papers regarding rudists in the Western Interior seaway. I just don't think this is another Durania. 

This is the closest I think I got to an identification of the new find:First_record_of_a_middle_Cenomanian_capr.pdf

 

 

 

Both come from the same Acanthoceras amphibolum zone. Could it be a Cobbanicaprina bighornensis?

 

I'd love to hear some input about this topic, and if anyone has any literature to share, please do, it would be much appreciated. 

Peace from New Mexico,

Chris 

 

 

[doushantuo]

Nice find,Opuntia!!!!

great story

edit : for Opuntia,read: Chris

Ben

Edited December 5, 2024 by doushantuo

[TqB]

Great story and good work.