Geological?

[MSirmon]

Found these in the San Angelo formation near Grape Creek, TX. I'm not sure what to make of the (as if that surprises any of the regular contributors in this forum). There were plenty of rocks in the area but these were different than the rest. 

 

On the first item the exterior is fairly hard but the interior is softer and disintegrates easily. I'm guessing a softer limestone?

 

The second is is very dense and has similar patterns to the belly of a tortoise or turtle. 

 

Any help or direction would be appreciated and thank you for your patience. 

 

Michael 

[Fossildude19]

Michael,

I think you have a concretion, and some septarian nodules.  

Regards,

 

[MSirmon]

Awesome! Thank you. I think I will dissolve the concretion to see what, if anything, is within. 

[ynot]

I agree with the first as a concretion.

I think the second one is mud cracks in limestone.

[Rockwood]

If those bubbles were gasses given off by a life form it could qualify as a trace fossil