Cladida

From Palaeos.org

Revision as of 07:39, 6 November 2008

o Echinodermata
`--+--Echmatocrinus brachiatus
   `--o Crinoidea
      |--Aethocrinida
      `--+--Disparida
         `--+--Camerata
            `--Cladida (incl. Flexibilia and Articulata)

Description

The Cladida are a group of Paleozoic crinoids that range from the Early Ordovician to the Late Permian. They are traditionally included in the Inadunata, but as this group has been shown to be polyphyletic they are awarded their own status as an independent subclass.

The dorsal cup is dicyclic, and there are three circlets of plates, consisting of radials, basals, and infrabasals. The crowns of some species attain a height of at least 30 cm.

Phylogeny

<==Cladida [Cladoidea, Dicyclica, Fistulata]
   |  i. s.: Plicodendrocrinus [Plicodendrocrinidae]
   |           `--P. casei (Meek 1871) [=Dendrocrinus casei]
   |         Pyrenocrinus
   |--*Compagicrinus fenestratus
   `--+--+--*Elpasocrinus radiatus
      |  |--Cyathocrinida
      |  `--Dendrocrinida
      `--Flexibilia [Anisocrininae, Articulosa, Flexibilida, Impinnata]
           |  i. s.: Archaetaxocrinus Lewis 1981
           |           `--*A. burfordi
           |         Asutaraecrinus Yakovlev 1956
           |--Taxocrinida
           `--Sagenocrinida [Sagenocrinoidea]
                |--Ichthyocrinidae
                |--Sagenocrinitacea
                `--Lecanocrinacea

* Type species of generic name indicated

References

Anon. 1978. Unassigned taxa. In Treatise on Invertebrate Paleontology pt. T. Echinodermata 2. Crinoidea (R. C. Moore & C. Teichert, eds.) vol. 3 p. T928. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

Ausich, W. I. 1998. Early phylogeny and subclass division of the Crinoidea (phylum Echinodermata). Journal of Paleontology 72 (3): 499-510.

Eckert, J. D., & C. E. Brett. 2001. Early Silurian (Llandovery) crinoids from the Lower Clinton Group, western New York State. Bulletins of American Paleontology 360: 1-88.

McIntosh, G. C. 2001. Devonian cladid crinoids: Families Glossocrinidae Goldring, 1923, and Rutkowskicrinidae new family. Journal of Paleontology 75 (4): 783-807.

Moore, R. C. 1978. Flexibilia. In Treatise on Invertebrate Paleontology pt. T. Echinodermata 2. Crinoidea (R. C. Moore & C. Teichert, eds.) vol. 2 pp. T759-T812. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

Moore, R. C., C. G. Lalicker & A. G. Fischer. 1952. Invertebrate Fossils. McGraw-Hill Book Company, Inc.: New York.

Credit

intro MAK061201, phylogeny CKT080225