Sadly, there aren’t enough features preserved for me to say if it’s a fossil or not. However, there are the two large black parts and smaller striations which makes me think wood and there are divots or holes in it so it could be terredo wood. Just due to the nature of the preservation it’s just too hard to say.

Hi @everett-snyder. You said this is from the Cannonball Formation? So this is from around North Dakota?

@bob-jones I think it might be Lirophora

It looks like two different colors of chert laid down one after the other. Sorry!

@bob-jones@rens-dewaard This is definitely a clam cast. It may take some time for me to find the name though.

@hunter-thurmond Calamites went extinct around the Triassic but their nearest living relatives in the genus Equisetum (same genus as modern horsetail) were around in the Paleogene. It’s possible it could be that. Can you remove some of the matrix? One of the key features is a node which might be covered right now. A cross section photo would help…[Read more]

@robin-loggains and @samantha-ocon Personally, I’m leaning towards septarian nodule with the original matrix eroded out but it’s a tricky one.

@delwin-glasner Very neat! I was unfamiliar with Endopachys. The only solitary scleractinian coral I encountered before was Flabellum. Thanks for sharing! Glad I learned something new.

To me this looks like horn coral. I think this is another photo in a series, yes?

Sorry, this is a rock. For fossils, we need to match the texture and shape to something known either living or fossil. It looks like the top is calcite and the bottom is probably a course limestone.

It’s a fossil but not a pirhana. Probably some sort of invertebrate like a crinoid stem or cephalopod or even a colonial animal. The rock sort of obscures the view.

Sorry this is a rock.

@robin-loggains It looks like a rock to me but the piece to the right of it is horn coral.

@bob-jones Thanks for posting more angles. It’s a horse tooth!

Sorry, this is a rock.

This looks like a fragment of rugose coral.

Looks like it could be a fragment of some Echinodermata based on the patterns of the depressions.

It looks like a piece of cement. Sorry.

Sorry, no fish. It’s a rock.