Pentacrinites fossilis, crinoid fossil. Crinoids are marine organisms, most of which have long stalks anchored to the seabed, with five or more feathery arms radiating from a central disc. Pentacrinites fossilis was unusual in that it lived suspended from floating driftwood (it is seen here attached to a log). This specimen is from Liassic rocks in Lyme Regis, Dorset, UK. It is part of the collections held at the Natural History Museum, London, UK.