Isocrinida
Isocrinida is an order of sea lilies which contains four 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.They are more mobile than other stalked crinoids, and can be found as shallow as, and on rare occasions below, but is most common at depths of.
Families
Ordo Isocrinida- Family Balanocrinidae Roux, 1981
- * Subfamily Balanocrininae Roux, 1981
- * Subfamily Diplocrininae Roux, 1981
- * Subfamily Isselicrininae Klikushkin, 1977
- * Subfamily Proisocrininae Rasmussen, 1978
- Family Cainocrinidae Simms, 1988
- Family Isocrinidae Gislén, 1924
- * Subfamily Isocrininae Gislén, 1924
- * Subfamily Metacrininae Klikushin, 1977
- Family Pentacrinitidae Gray, 1842
- * Subfamily Eocomatulinae Simms, 1988
- * Subfamily Pentacrinitinae Blumenbach, 1804