Unknown Bivalve From The Navesink

[njfossilhunter]

I found this Bivalve in the Navesink Fm in a Monmouth County Brook and I'm not sure what to make of it. anybody here have any ideas about it ????

The shell measures 21mm long and 13mm at its widest . 

 

 

 

[Herb]

my guess is Gryphea sp.

 

[Rockwood]

Second,

[njfossilhunter]

13 hours ago, Herb said:

my guess is Gryphea sp.

 

 

8 hours ago, Rockwood said:

Second,

 

What makes you think its a Gryphea sp....? I have Richards two volume set of The Cretaceous fossils of NJ  and it doesn't have any photos that looks like this specimen. I sent photos to Ralph Johnson a local expert on cretaceous coastal plains invertebrates and all he can tell me that it looks orsteroid  and maybe some what eroded and possibly something new..but didn't  give it a species name. I'm going to send some photos to other people in hopes of  finding what this little guy is.

[Rockwood]

To be honest, 'they look like devilish toenails' is about all I have. 

[njfossilhunter]

1 hour ago, Rockwood said:

To be honest, 'they look like devilish toenails' is about all I have. 

 

LMHO.......

[Rockwood]

23 minutes ago, njfossilhunter said:

 

LMHO.......

What can I say. I used up my daily prudence on the whale vert..

[Herb]

it looks like a Gryphea sp missing the peak and the flat part looks like the operculum with the one muscle scar.

[njfossilhunter]

I got a email from George Phillips of the Mississippi natural history museum today and he was able to shed a lot of light on what I found, It turned out to be either a Ambigostrea tecticosta gabb or a Agerostrea mesenterica morton. Since mine is a right valve that would attach to a Octocoral like a sea pen or a gorgonian it would make it difficult to say which specie it would be depending on how it would attach them self to the Octocoral as you can see from the posted photo he sent me. Its the left valve that would be whats diagnostic.