Fossil found at Grand Lake Northwest Oklahoma

[craigmontgomery]

Found this fossil when I was a kid at Grand Lake, Northwest Oklahoma.  It was along the shore line.  Any idea what it is?  

[Raggedy Man]

It's an internal cast of a crinoid stem. Below is a picture of a similar specimen.

Best regards,

Paul

 

[Fossildude19]

+ 1 for Crinoid internal cast. 

Yours looks to have been in the process of being covered with Beekite. 

Neat find.

Regards,

[DPS Ammonite]

You have a rather interesting crinoid fossil that shows two types of body fossils in one piece. Usually fossils are either molds or original body/cast of body fossils. The first shows the infilling of the hollow internal spaces of a crinoid column, an internal mold. The second photo shows the exterior of the crinoid stem (original calcite?) that might be a cast if the original calcite has been replaced with something else such as chert (Beekite.) If the fossil is made of chert, this is probably what happened: chert replaced or created an interior mold. The chert then partially replaced the original calcite on the exterior of the column. Then the original calcite of the column dissolved.

 

Is your fossil made of chert or calcite?

[abyssunder]

I agree with the others. Nicely eroded/geodized crinoid columnal revealing also what was once the internal structure. Similar examples are presented here :