Agassizocrinacea

Cup of Paragassizocrinus tarri, from here.

Belongs within: Dendrocrinida.

The Agassizocrinacea are a group of crinoids known from the Lower Carboniferous to Upper Permian (Moore et al. 1978).

Characters (from Moore et al. 1978): Crown cylindrical to pear-shaped. Cup bowl-shaped with convexly round base; infrabasals five or fused into single solid plate; readily visible from side; radial articular facets wide, occupying full width of radial summits; anal plates in cup none to four, joined very tightly in some to few lower posterior sac plates so as to form in effect upward projection of cup margin. Anal sac variably weak to strong, cylindrical or mushroom-shaped. Arms mostly numerous, isotomously branched on primaxils and heterotomously above. Stem transversely round or exceptionally pentagonal or pentalobate.

Agassizocrinacea
    |--Cricocrinus Strimple & Watkins 1969 [Cricocrinidae] ML78
    |    `--*C. regulatus (Strimple 1949) [=Paradelocrinus regulatus] ML78
    |--Trimerocrinus Wanner 1916 [Trimerocrinidae] ML78
    |    |--*T. pumilus Wanner 1916 ML78
    |    `--T. ventricosus ML78
    |--Bursacrinidae ML78
    |    |--Bursacrinus Meek & Worthen 1861 ML78
    |    |    `--*B. wachsmuthi Meek & Worthen 1861 ML78
    |    |--Lebetocrinus Kirk 1940 ML78
    |    |    `--*L. grandis Kirk 1940 ML78
    |    `--Nactocrinus Kirk 1947 ML78
    |         `--*N. nitidus Kirk 1947 ML78
    |--Agassizocrinidae [Paragassizocrinidae] ML78
    |    |--Anartiocrinus Kirk 1940 ML78
    |    |    `--*A. lyoni Kirk 1940 ML78
    |    |--Epipetschoracrinus Yakovlev in Yakovlev & Ivanov 1956 ML78
    |    |    `--*E. borealis Yakovlev in Yakovlev & Ivanov 1956 ML78
    |    |--Petschoracrinus Yakovlev 1928 ML78
    |    |    `--*P. variabilis Yakovlev 1928 ML78
    |    |--Agassizocrinus Owen & Shumard 1852 (see below for synonymy) ML78
    |    |    |--*A. conicus Owen & Shumard 1852 ML78
    |    |    `--A. laevis (Roemer 1854) [=*Astylocrinus laevis] ML78
    |    `--Paragassizocrinus Moore & Plummer 1940 ML78
    |         |--*P. tarri (Strimple 1938) [=Agassizocrinus tarri] ML78
    |         `--P. kendrickensis ML78
    `--Sundacrinidae ML78
         |--Sundacrinus Wanner 1916 ML78
         |    `--*S. granulatus Wanner 1916 ML78
         |--Basleocrinus Wanner 1916 ML78
         |    `--*B. pocillum Wanner 1916 ML78
         |--Hemiindocrinus Yakovlev 1926 ML78
         |    `--*H. fredericksi Yakovlev 1926 ML78
         |--Laccocrinus Wanner 1949 ML78
         |    `--*L. scrobiculatus (Wanner 1924) [=Basleocrinus scrobiculatus] ML78
         |--Parindocrinus Wanner 1937 ML78
         |    `--*P. oyensi Wanner 1937 ML78
         `--Tribrachyocrinus M’Coy 1847 [=Tribrachiocrinus Wachsmuth & Springer 1886] ML78
              |--*T. clarkii M’Coy 1847 [=*Tribrachiocrinus clarkii] ML78
              |--T. corrugatus Ratte 1884 F71
              |--T. granulatus Etheridge 1892 F71
              `--T. ornatus Etheridge 1892 F71

Agassizocrinus Owen & Shumard 1852 [incl. Agassizocrinites Troost 1850 (n. n.), Astylocrinus Roemer 1854] ML78

*Type species of generic name indicated

REFERENCES

[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).