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 , 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 .[ Globally discordant Isocrinida (Crinoidea) migration confirms asynchronous Marine Mesozoic Revolution]
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, Shemshak Group, 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
-
Hess H (2011) Isocrinida. In: Hess, H., Messing, C.G., Ausich, W.I. (Eds.), Treatise on Invertebrate Paleontology, Part T, Echinodermata 2 Revised, Crinoidea, vol. 3. University of Kansas Press, Lawrence, Kansas, pp. 42–69.
