Isocrinida

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 Image:Endoxocrinus parrae.jpg|Endoxocrinus parrae (Balanocrinidae) Image:Britannica Echinoderma 14.jpg|Isocrinus asteria File:Crinoid_fossils_the_Jurassic.jpg|Isocrinus fossil, Shamshak Formation, Alborz province, Iran Image:Metacrinus rotundus by OpenCage.JPG|Metacrinus rotundus (Isocrinidae) Image:Neocrinus decorus.jpg|Neocrinus decorus (Balanocrinidae) Image:Proisocrinus ruberrimus.jpg|Proisocrinus ruberrimus (Balanocrinidae) Image:Endoxocrinus.jpg|Endoxocrinus sp. (Balanocrinidae) File:Crinoide vraie.jpg|Unidentified Isocrinid ==References==