Mollusk and something else I think

[OregonFossil]

Need some ID help on this one. Eocene, Keasey Formation, and an inclusion or something inside a concretion. Size of the whole piece is 12 x 15 cm, weighs about 6 pounds.

 

Image 1 - Mollusk on top of something that has included into the matrix

 

#2 is a close up of the mollusk and surrounding area

 

Closeup of the inclusion material

 

More images to follow.

 

 

Edited January 6, 2021 by OregonFossil
Spelling

[OregonFossil]

Layer surrounding the inclusion:

Another closeup of the inclusion:

 

Interesting intersection of the outer layers and the inclusion:

 

Anyone know what the inclusion is? I am thinking maybe a coral?

 

[Fossildude19]

Looks like it is just part of the concretion, to me.  

 

[badeend]

Hello,

 

I think it s a geological feature, not a fossil.

 

greetings Walter

[OregonFossil]

Here are two replies from PhD's:

 

Rock ID from photos is tricky, but my best guess is a bivalve (the white area) surrounded by an "aureole" of mineral precipitation caused by original animals decay in the sediment. This is definitely a guess though! Very fascinating rock — it also looks like a concretion that has split in half. 

 

This looks like a partial shell or shells of some kind of bivalved mollusk in a concretion, which is not uncommon in the Keasey Formation. The surrounding textured material looks like dendrites and/or diagenetic minerals and/or is from later weathering, not fossil material. Fun find!