Cladida (original) (raw)

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Parvclass of crinoids

CladidaTemporal range: Ordovician–recent PreꞒ Ꞓ O S D C P T J K Pg N
Ulrichicrinus coryphaeus, a eucladid from the Mississippian-age Edwardsville Formation
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Crinoidea
Subclass: Pentacrinoidea
Infraclass: Inadunata
Parvclass: CladidaMoore and Laudon (1943)[1]
Subgroups
†Porocrinoidea †Flexibilia Eucladida †Ampelocrinida †Cyathoformes Articulata

Cladida is a major subgroup of crinoids with a complicated taxonomic history. Cladida was originally applied to a wide assortment of extinct crinoids with a dicyclic calyx. Under this original definition, cladids would represent a paraphyletic order ancestral to several other major crinoid groups, particularly the living Articulata. More recently, Cladida has been redefined as a monophyletic parvclass of pentacrinoids which encompasses articulates and the extinct Flexibilia (flexibles). Cladids also include various minor taxa such as the hybocrinids and "cyathocrines". As flexibles were not originally considered cladids, the new subgroup Eucladida has been erected for cladids which are more derived than flexibles. Cladida is the sister group to Disparida, another large group of extinct crinoids.[2]

  1. ^ Evolution and Classification of Paleozoic Crinoids, Raymond Cecil Moore, Lowell Robert Laudon, 1943
  2. ^ a b c d Wright, David F.; Ausich, William I.; Cole, Selina R.; Peter, Mark E.; Rhenberg, Elizabeth C. (2017). "Phylogenetic taxonomy and classification of the Crinoidea (Echinodermata)". Journal of Paleontology. 91 (4): 829–846. doi:10.1017/jpa.2016.142. ISSN 0022-3360.
  3. ^ a b c d e Wright, David F. (2017-10-23). "Phenotypic Innovation and Adaptive Constraints in the Evolutionary Radiation of Palaeozoic Crinoids". Scientific Reports. 7 (1): 13745. doi:10.1038/s41598-017-13979-9. ISSN 2045-2322. PMC 5653864.

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