Turtle shells?

[Wyohobby]

Good evening!
 

I have so enjoyed reading all your posts on the fossil ID over the past month. It is fascinating to witness the knowledge and enthusiasm of your members! 
 

Tonight I’m sharing possible turtle shells my mother picked up in The Wind River basin near Riverton Wyoming. I think this area is Cenozoic.  It has a lot sandstone but she recalls these were just laying on the ground among other normal rocks. 
 

We have many pieces but I am just sharing a few representative items here. I’d love to know anything more about them. Are they possibly turtle? Any guesses as to what kinds?  What are the odd shapes on item 1? Is item 4 a bone? 

Thank you so much for your time and expertise! I look forward to learning more. 

 

 

 

 

[PaleoNoel]

First piece is a crocodilian osteoderm. I could see how one could think it was turtle shell, but croc osteoderms generally have larger and deeper pits than the dimpled texture seen in softshell turtles.

Second and third appear to be turtle shell but hard to be sure.

Fourth and final piece is a section of bone, potentially limb. Probably not identifiable beyond that.

@jpc has many years of experience in Wyoming, which I believe includes Wind River formation. 

[caterpillar]

I think 4 is a part of croc femur

[Wyohobby]

Thanks so much! This is very neat to hear- I did find the depressions very odd.
 

I’ll add a photo of the whole set: let me know if something catches your eye and I can take better photos.   Also attached is a close up of one example. 
 

In a nearby location my mom also found a whole turtle shell (top and bottom) which she retrieved. But despite these successes of my mom’s, years of hopeful searching by kids and grandkids have turned up nothing else. It’s great to know more about what she did find. 
 

I’ll post the turtle next time I visit it.