Astrocrinidae

(From top to bottom) oral view, aboral view, and D-ray view of Astrocrinus benniei, from Beaver et al. (1967).

Belongs within: Blastoidea.

The Astrocrinidae are a Devonian to Permian group of blastoids. The genera Astrocrinus and Tripoblastus are believed to have been free-living, sitting directly on the sea floor without an attaching stalk (Waters et al. 2003).

Characters (from Beaver et al. 1967): Theca with eight spiracular slits along margins of ambulacra; anal side lacking slits.

<==Astrocrinidae [Astracrinidae, Pentephyllidae, Zygocrinidae]
    |  i. s.: Tripoblastus Waters, Maples et al. 2003 WM03
    |           `--*T. plicatus Waters, Maples et al. 2003 WM03
    |         Pentephyllum Haughton 1859 BF67
    |           `--*P. adarense Haughton 1859 BF67
    |--Cryptoschisma Etheridge & Carpenter 1886 BF67
    |    `--*C. schultzii (de Verneuil & d’Archiac 1845) [=Pentremites schultzii] BF67
    `--+--Ceratoblastus Wanner 1940 BF67
       |    `--*C. nanus Wanner 1940 BF67
       |--Pentremitidea d’Orbigny 1850 [=Pentetrematites Steininger 1849, Pentremitidia Quenstedt 1876] BF67
       |    `--*P. pailletti (de Verneuil 1844) (see below for synonymy) BF67
       `--Astrocrinus Morris 1843 (see below for synonymy) BF67
            |--*A. tetragonus Morris 1843 (see below for synonymy) BF67
            `--A. benniei BF67

Astrocrinus Morris 1843 [=Astracrinites Austin & Austin 1843, Astrocrinites Austin & Austin 1843 non Conrad 1841, Zygocrinus Bronn 1848] BF67

*Astrocrinus tetragonus Morris 1843 [=Astrocrinites tetragonus Austin & Austin 1843 (n. n.), Astracrinites tetragonus, *Zygocrinus tetragonus] BF67

*Pentremitidea pailletti (de Verneuil 1844) [=Pentremites pailletti, *Pentetrematites pailletti, *Pentremitidia pailletti] BF67

*Type species of generic name indicated

REFERENCES

[BF67] Beaver, H. H., R. O. Fay, D. B. Macurda Jr, R. C. Moore & J. Wanner. 1967. Blastoids. In Treatise on Invertebrate Paleontology pt. S. Echinodermata 1. General characters. Homalozoa-Crinozoa (except Crinoidea) (R. C. Moore, ed.) vol. 2 pp. S297-S455. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).

[WM03] Waters, J. A., C. G. Maples, N. G. Lane, S. Marcus, Liao Z.-T., Liu L., Hou H.-F. & Wang J.-X. 2003. A quadrupling of Famennian pelmatozoan diversity: New Late Devonian blastoids and crinoids from northwest China. Journal of Paleontology 77 (5): 922-948.