Isocrinida

Isocrinida is an order of sea lilies which contains four families.

Pentacrinites is an extinct genus of crinoids that lived from the Hettangian to the Bathonian of Asia, Europe, North America, and New Zealand. Their stems are pentagonal to star-shaped in cross-section and are the most commonly preserved parts. Pentacrinites are commonly found in the Pentacrinites Bed of the Early Jurassic (Lower Lias) of Lyme Regis, Dorset, England. Pentacrinites can be recognized by the extensions (or cirri) all around the stem, which are long, unbranching, and of increasing length further down, the very small cup and 5 long freely branching arms.

Isocrinidae is one of four extant families of crinoids in the order Isocrinida.

Neocrinus is a genus of crinoids in the family Balanocrinidae, which is otherwise extinct (this genus being a relict). Members of this genus appeared in the fossil record 23.03 million years ago in the Miocene Epoch, and currently contains three known extant species.