cmccartor 的鑑定

Commentary from Dr. Charles Frederick:

That looks to me like a gastropod or snail. Animals like snails can be preserved as the actual shell, a mold of the shell (like that left by pressing the shell into soft dirt), or as internal Casts of the shell (also called a steinkern). This is gastropod steinkern(in my opinion).
That said I suspect that is Cretaceous in age (it looks like a lot of fossil snails I have seen of that age), but I have doubts I would recognize a coprolite of that age…. Even some of the human virility’s we have from rock shelters in west Texas don’t look like poop in the traditional sense. But having not seen any real unambiguous coprolites of that age (and the age is clearly a wild guess on my part here) I don’t have a good mental image or template.