Isocrinida

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

Characteristics
Members of this order are characterised by having a "heteromorphic" stalk; the stalk consists of a series of nodes with cirri, interspersed by several nodes without cirri. There are additionally a whorl of cirri at the base on which the animal perches. The calyx is a shallow cup consisting of five basals and five radials.

Families

 * Suborder Isocrinina Sieverts-Doreck, 1952
 * family Cainocrinidae Simms, 1988 -- 1 genus (1 species)
 * family Isocrinidae Gislén, 1924 -- 3 genus (3 species)
 * family Isselicrinidae Klikushkin, 1977 -- 4 genus (18 species)
 * family Proisocrinidae Rasmussen, 1978 -- 1 genus (1 species)
 * Suborder Pentacrinitina Gray, 1842 †
 * family Pentacrinitidae Gray, 1842 †