Nodule, matrix, or whatever.

[JoeDINO]

Ku2 

Hunt County, TX

 

This is about the size  of a car tire.  These are typically heavy in mineral deposits on their interior with some perceived chambering. I've recovered quite a few over the past year that are very similar but none I've ever come across have had the exterior features like this one. It also carries that same orange color that I'm observing in a lot of the collected items. (Collage pic is of two others examples of the coloring referenced.)

 

I've been pointed towards septerian nodules before with a similar submission. I've read some of the research on them and while some characteristics fit, others do not. It's heavy enough that I opted to go with the one-sided picture and see if there was an interest first before q flipping it on the other side and potentially damaging some features. 

The bivavle, Exogyrabivavle ponderosa I believe, was found nearby. It's about 8" at its widest point. 

 

Thank you

 

[DPS Ammonite]

The top 4 photo show inoceramid bivalves such as Inoceramus. The exogrya looks to be the semicostata variety.

[JoeDINO]

Thank you for the prompt response. I can definitely see that journal similarities now in a lot of the specimens I have. Is there any research available regarding their insides? Here's the others...