Isocrinida is an order of
sea lilies
Crinoids are marine invertebrates that make up the Class (biology), class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or ...
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.
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
Alborz province () is one of the 31 provinces of Iran. Its capital is the city of Karaj, which lies 10 km west of Tehran, at the foothills of the Alborz mountains. Alborz is Iran's smallest province in area.
History
In 2010, Karaj ...
, 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
*Hess H (2011) Isocrinida. In: Hess, H., Messing, C.G., Ausich, W.I. (Eds.),
Treatise on Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...
, Part T, Echinodermata 2 Revised, Crinoidea, vol. 3. University of Kansas Press, Lawrence, Kansas, pp. 42–69.
Articulata (Crinoidea)
Anisian first appearances
Extant Middle Triassic first appearances
Echinoderm orders
{{crinoidea-stub