Hi, I found this near Ludlow, Shropshire. It looks like a Pine Cone - is it?
I think the stone is some form of Limestone.
Hmmm - I don't see any structure within the bands or across the 'end'.
There's a very superficial resemblance to Eurypterid abdomen
But I think that, too, does not apply here.
I can't be sure, but I get the impression the bands are the surface representation of flat layers, intersecting the surface of the specimen which happens to be somewhat cone-shaped. (There are other geometrical possibilities such as cones in cones, and there is a phenomenon called cone-in-cone structure, but this is not that.) Weathering has eroded the weaker (brownish) laminae between the layers, creating a slightly stepped appearance.
So I think it is probably a concretion (nodule if you like) that has developed across the primary sedimentary layering in the limestone (I think you're probably right on it being limestone).
Fossil conifer cones do exist, though. Here's a fine Araucaria (monkey puzzle) cone from the Jurassic
- example of concretions, at Nodule Point, Washington, USA - http://nwgeology.wordpress.com/the-fieldtrips/geology-trip-to-nodule-point-marrowstone-island%C2%A0washington/
- my description of the formation of concretions - http://www.nhm.ac.uk/natureplus/message/27257#27257(yours is a little different in that it does not have any concentric banding)
Update 04jun13: see John's correct ID as Gomphoceras below
Hi Mike, Many thanks for your reply. The area does contain beds of Limestone nodules, but I have not seen any of this shape and can't remember seeing any with concentric lines. Of course nature has a wonderful way of creating random shapes to fool us into seeing something that was never real.
I've taken another picture of the base of the "Cone" there appears to a stalk...
I suspect you are right, but this remiinds me of a "green" - immature cone before the seed scales have opened.
Message was edited by: john451
I see what you mean about the 'stalk', but I'm not sure I can ascribe much significance to it.
If you are prepared to cut it in half (eg. with angle grinder or rock saw - very carefully for your own safety), we might learn some more - eg. if the 'stalk' continues, and if the layering runs straight through. Your call, of courase.
I decided to look locally - and success! It's a Gomphoceras.