Any Geoligests here

Cuda Hunter said
The rock appears to have an oyster shell in it. The rounded part that kinda looks like an ear.
Try this, if you want a google search.
Oyster-encrusted Cremnoceramus deformis shell fragments

I cannot disagree. Now that you mention it......who knows what it is? I sure don't. It's super cool though, especially as big as it is.