Triacrinus elongatus, from Bundenbach Fossilien.

Belongs within: Disparida.

The Pisocrinidae are a group of small crinoids known from the Middle Silurian to Upper Devonian, with the cup composed primarily of three relatively lage plates.

Characters (from Moore et al. 1978): Small crinoids with globose or conical cup. Basals three or five; three small radials (corresponding to B, C and E compound radials of Homocrinidae) and two large radials, inferradial of B ray hypertrophied and displaced obliquely to right, forming with large A and D radials most of cup. Tegmen poorly known, anal opening above cup. Arms atomous and nonpinnulate or with two main ramule-bearing rami to a ray.

Pisocrinidae [Cicerocrinidae, Pisocrinacea, Pisocrinidées, Triacrinidae]
    |--Calycanthocrinus Follman 1887 ML78
    |    `--*C. decadactylus Follman 1887 ML78
    |--Jaekelicrinus Yakovlev 1949 ML78
    |    `--*J. bashkiricus Yakovlev 1949 ML78
    |--Pisocrinus de Koninck 1858 [incl. Triacrinus Ringueberg 1884 non Münster 1839] ML78
    |    |--*P. pilula de Koninck 1858 ML78
    |    `--P. yassensis Etheridge 1904 [incl. P. yassensis var. lobata Etheridge 1904] F71
    |--Cicerocrinus Sollas 1900 [incl. Lagarocrinus Jaekel 1901] ML78
    |    |--*C. elegans Sollas 1900 ML78
    |    `--‘*Lagarocrinus’ osiliensis Jaekel 1901 ML78
    |--Parapisocrinus Mu 1954 [=Ollulocrinus Bouška 1956] ML78
    |    |--*P. ollula (Angelin 1878) [=Pisocrinus ollula, *Ollulocrinus ollula] ML78
    |    `--P. quinquelobus ML78
    `--Triacrinus Münster 1839 [incl. Trichocrinus Müller 1856] ML78
         |--*T. pyriformis Münster 1839 ML78
         |--T. altus (Müller 1856) [=*Trichocrinus altus] ML78
         |--T. elongatus ML78
         `--T. regnelli ML78

*Type species of generic name indicated


[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1-167.

[ML78] Moore, R. C., N. G. Lane, H. L. Strimple, J. Sprinkle & R. O. Fay. 1978. Inadunata. In Treatise on Invertebrate Paleontology pt. T. Echinodermata 2. Crinoidea (R. C. Moore & C. Teichert, eds) vol. 2 pp. T520-T759. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

No comments:

Post a Comment

Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="http://www.fieldofscience.com/">FoS</a> = FoS