Isocrinida
Isocrinida Temporal range: | |
---|---|
Isocrinus nicoleti columnals; Middle Jurassic; Carmel Formation; Utah. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Crinoidea |
Subclass: | Articulata |
Order: | Isocrinida |
Isocrinida is an order of sea lilies which contains four extant families.
Characteristics
[edit]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.[1]
Families
[edit]- Suborder Isocrinina Sieverts-Doreck, 1952
- family Cainocrinidae Simms, 1988 -- 1 genus (1 species)
- family Isocrinidae Gislén, 1924 -- 3 genus (3 species)
- family Isselicrinidae Klikushkin, 1977 -- 4 genus (18 species)
- family Proisocrinidae Rasmussen, 1978 -- 1 genus (1 species)
- Suborder Pentacrinitina Gray, 1842 †
- family Pentacrinitidae Gray, 1842 †
- Endoxocrinus sp.
References
[edit]- ^ O'Hara, Timothy; Byrne, Maria (2017). Australian Echinoderms: Biology, Ecology and Evolution. Csiro Publishing. p. 192. ISBN 978-1-4863-0763-0.
- 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.