Uintacrinus socialis (by afagen on Flickr)Seeing as most of my new fossils contain types of crinoids, I thought I’d do a quick post about these guys!
The above crinoid is called Uintacrinus socialis, and it is from the Cretaceous period. Crinoids are more commonly known as “sea lilies” and “feather stars”, and belong to the phylum Echinodermata. The great thing about crinoids is that they are still around today! These awesome guys are yet another example of living fossils. Though instead of a stem, Uintacrinus socialis had a globular cup, which as you can see above is composed of polygonal plates. The arms of Uintacrinus socialis were quite long, reaching up to around 1 metre in length! These arms are used to filter food through the water.
In general, crinoids came onto the scene during the Ordovician period and have lived in the seas ever since, adapting well when selective extinctions occurred. Though, crinoids were also much more prevalent in ancient seas. The fossils I discovered a few weeks ago date back to around 400 million years ago, which is pretty amazing stuff. I found a very well preserved section of a crinoid stem in Chert - which is a very durable sedimentary rock - and the detail of the stem is just absolutely fantastic!
Much love for the crinoids, as always.
