Yorktown Formation ID

[msomma12]

Two species from the Yorktown Formation along the James River in Virginia that I cannot identify. One a coral (if not genus name, family?) and the other what I presume to be part of a bivalve. Both are very common yet I cannot find them in any references. Any help would be appreciated. Thanks.

[Tidgy's Dad]

Hello.

The one on the left looks like a sponge to me. 

[caldigger]

23 minutes ago, Tidgy's Dad said:

Hello.

The one on the left looks like a sponge to me. 

Agreed

 

For the shell fragments, I came up with

Atlantic Ribbed Mussels.  How do these compare?

[sixgill pete]

I believe the left one is a bryzoan. We find very similar ones in the Yorktown here in North Carolina. As far as the bivalve pieces. I do not believe there is enough to make an accurate guess. 

[hemipristis]

5 hours ago, msomma12 said:

Two species from the Yorktown Formation along the James River in Virginia that I cannot identify. One a coral (if not genus name, family?) and the other what I presume to be part of a bivalve. Both are very common yet I cannot find them in any references. Any help would be appreciated. Thanks.

 

I offer the following:  

 

A species of cockle, Genus Isocardium (first two photos), or an arc, Genus Anadara (3rd photo). 

 

Drawings from the classic Lauck Ward publication Mollusca of the Miocene/Pliocene of VA & NC.  It''s an excellent reference to have if one collects Neogene fossil shells

[Al Dente]

7 hours ago, sixgill pete said:

I believe the left one is a bryzoan. We find very similar ones in the Yorktown here in North Carolina.

I agree.

[msomma12]

Thanks everyone!