Mystery items from LC: Marine mammal?

[hemipristis]

Here are a pair of head-scratchers that I found i at LC.  The first is from the Pungo River Fm I thought was a bivalve steinkern, but it is not carbonate, which one would expect in the lime layers of the formation (that, or phosphate, and itisnt phosphate).  There is still some matrix on it. So that leaves me with maybe some portion of the bulla/ear region of a marine mammal, but that's purely a guess.

 

The second is from the Pliocene Yorktown Fm, and the material appears to be the same as that of cetacean tympanic bulla.  But it doesn't look like one, or like anything Ive seen from a cetacean.  Any ideas?

 

thanks

 

 

[Al Dente]

The first is a bulla, the second is a broken piece of a periotic.