Septarian Nodule, or maybe bone?

[dhiggi]

Found this today in the Whitby area, either a septarian nodule is playing a cruel, early April fools or it’s some kind of reptile bone. It’s roughly symmetrical with the circle shape on each side. 
 

Thanks for looking.

[TqB]

I think it's more probably a nice piece of wood. It should cut and polish very well, probably to show microscopic detail. 

Edited March 29, 2021 by TqB

[dhiggi]

Thanks @tqb , I didn’t think of that but it seems quite obvious 

[dhiggi]

Wood too? Wasn’t sure on this one but my daughter carried it back just in case it was of interest 

[dhiggi]

Pretty sure these are bone, one is likely just an unidentifiable chunk, but is there anything diagnostic about the shapes in the rock with a few pieces?

[TqB]

I agree the rest look like bone, including the first one (your daughter's) which is perhaps Gyrosteus.

[dhiggi]

2 minutes ago, TqB said:

I agree the rest look like bone, including the first one (your daughter's) which is perhaps Gyrosteus.

Thanks Tarquin, that’s put a smile on her face (she found all three)