I found this on a beach in Bude, North Cornwall last week. Its shape is very regular and looks like a seed, does anyone know what it might be?
Things like this are usually either seeds or concretions.
If it is a seed it may have some characters identifying it as such. So please look at the pointed ends: do you see any sign of a scar where the stem or stigma might have been attached? Also see if there is any sort of seam. Such seams might be one (going right round), three, or more; they would go from end-to-end.
If it does not have any of that, it is ambiguous: it could be a concretion, but it could still be a seed (sometimes the details are absent).
In any case, please take some more photos, showing it from the ends and all round. Maybe I can see something you can't, due to experience.
Thanks for your reply.
There seems to be a scar and a faint seam, but I'm not sure about this!
I hope the pictures help a little.
Thanks for the further photos.
I don't see anything truly characteristic of a seed.
The 'seam' could well just be a slightly siltier layer in the sediment.
But the last photo suggests a slight division into perhaps quarters, with slightly sunken areas between the 'ribs', which might suggest a seed.
The specimen probably came from the Bude Formation, which is Carboniferous in age (about 315m years ago) - so plants would have been around at that time. However, the rocks are poor in fossils generally, and the only plant fossils seem to be highly fragmented. Concretions (some quite large) are known. There is a detailed account here - http://ww.geoclastica.com/Higgs91BudeFm.pdf
Bearing all the above in mind, I think it slightly more likely that your specimen is a concretion.
If you want another opinion, I suggest you follow the 'local knowldge' route...
You could enquire at the Bude Museum (Bude Castle Heritage Centre, rather than the Bude & Stratton Town Museum). I know it has at least one fossil (a fish), but I see no mention of geology on their web site - http://www.thecastlebude.org.uk.
Maybe you'd do better contacting Dr Roger Higgs, who organizes the Bude geological walks
Please let us know what progress you make.
Does it have three ridges or just one at the front? If it has three, it is likely to be a trigonocarpus seed, but if it just has one it's probably just a concretion as mike said. The shape of it does look very much like a trigonocarpus seed, but many concretions can be that shape.