
Feather Star Crinoid Fossil
These star-shaped fossils are a type of crinoid stem segment from the Jurassic Period. They are sometimes called Feather Stars and if you look close enough to see the fine details, you can see why. Crinoids are marine organisms, and members of the phylum Echinoderm. Like other organisms of this group— including starfish, sea urchins, and sand dollars—they form in recognizable 5-point radial symmetry. Crinoids as a whole are among the oldest living lineages on Earth. Recent fossil discoveries have extended their known existence into the Darriwillian up to 467 million years ago. Although they were much more abundant in the past, about 600 species of crinoid still exist today. These star-shaped crinoids were discovered in Moroccan fossil beds dated to around 170 million years old.