Weird find

[stacylaray]

Found today, Ladonia Fossil Park, North Sulphur River, in 4" of water among river rocks and the occasional piece of ammonite with suture pattern.  I don't know what period.  A little over an inch long, black/dark gray, 1/2 inch thick at the widest part, has holes on the underside.  

[connorp]

From what I've read, Cretaceous fossils are found on the river bed and Pleistocene fossils on the banks. So likely Cretaceous but possibly not. I can't help on the ID, but larger pictures would certainly help others.

[Pterygotus]

If it has the ‘honeycomb’ pattern then it’s bone. I think that’s what the holes are but can’t be sure with the pictures. Nice find!

[Peat Burns]

Looks like a mollusk steinkern with burrows