Articulating joint?

[LKett]

I grew up in the creeks, rivers, woods, caves, lakes and bluffs of western Cedar County

Missouri in the Osage Plaines next to the Ozark Plateau. I've always been a rock hound but this world is new to me and there is a lot to learn, please be patient. As I was rehabing my knee outside of town on a dirt road, I started finding some petrified wood and other interesting finds, one of which looks like part of a petrified animal joint bone. The reasons as to why I believe it could be bone: First, is the shape. Looks like an articulating joint. Second, has hairline cracking typical of dead dry bone. Third, the cell structure, especially visible on the broken side has the porous, fibrous look and feel of dead dry bones. Fourth, I have found 2 other specimens in the past month that appear to be bone from the same site within 10 meters of each other. From what I'm reading, there shouldn't be fossilized animal bone in this area so I don't know what to think.

What do I have?

[ynot]

Could be petrified wood or an opallite - hard too be sure with no closeup shots.

 

So far my vote is for opalite.

 

PS the rough side is adhering matrix.

Edited May 8 by ynot

[Ludwigia]

Definitely not bone at any rate.

[C2fossils]

Flint/Chert Nodule