Thank you to everyone who had a guess as to what on earth this alien-looking object was.
It is, in fact, the mouth parts of a sea urchin. Well done to those of you who were very close, and in particular to Colin at The Scottish Aeneas, who was spot on!
Colin (not the same one, I mean my husband!) found it on the beach below Dunnottar Castle and photographed it in situ before bringing it back as a very interesting souvenir. I believe the species is the Common (or Edible) sea urchin, Echinus esculentus – but if I’m wrong, please correct me!
I must admit that I would have been hard pushed to identify it. Nature can be stranger than fiction!
Here is a photo of the sea urchin on the beach; you can see the mouth parts in the middle, pointing downwards. The complex structure consists of calcium plates, muscles and connective tissue; it was first described by Aristotle, and it is also known as ‘Aristotle’s lantern’. (You can read more about it on this page from the Natural History Museum.) The five ‘teeth’ are self-sharpening, and as the animal feeds they have an erosive action that is capable of grinding rock into sand.
Photos copyright © Colin Woolf