Dr Katie StrangHere’s some wee 330 million year old crinoid ossicles that wonderfully illustrate their five-fold radial symmetry. Nature is awesome 🖤 #ScottishFossils #ScottishGeology
Michael Busch@palaeokatie @astrokiwi The crinoids in the 440-million-year old limestone under my house in Minnesota still have five-fold symmetry, but it is not so dramatic.
Now I am wondering about echinoderm evolution...