Here’s some wee 330 million year old crinoid ossicles that wonderfully illustrate their five-fold radial symmetry. Nature is awesome 🖤 #ScottishFossils #ScottishGeology
@palaeokatie
Daughter now looking up ossicles. Thanks!
@equalitysiren there’s something good info on the British Geological Survey website 😀 https://www.bgs.ac.uk/discovering-geology/fossils-and-geological-time/crinoids/
Crinoids - British Geological Survey

Crinoids are an ancient fossil group that first appeared in the seas of the Middle Cambrian, about 300 million years before dinosaurs.

British Geological Survey