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.^[2]

They are more mobile than other stalked crinoids, and can be found as shallow as 100–170 m (300–600 ft), and on rare occasions below 400 m (1,300 ft), but is most common at depths of 200–300 m (700–1,000 ft).^[3]

Ordo Isocrinida^[1]

• 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

• 
  Endoxocrinus parrae (Balanocrinidae)
• 
  Isocrinus asteria
• 
  Isocrinus fossil, Shamshak Formation, Alborz province, Iran
• 
  Metacrinus rotundus (Isocrinidae)
• 
  Neocrinus decorus (Balanocrinidae)
• 
  Proisocrinus ruberrimus (Balanocrinidae)
• 
  Endoxocrinus sp. (Balanocrinidae)
• 
  Unidentified Isocrinid