Lecanocrinacea

Silurian Lecanocrinus macropetalus, from here.


Belongs within: Cladida.

The Lecanocrinacea are a group of Upper Silurian to Upper Permian crinoids with a typically short and subglobular crown and well-delimited cup and arms.

Characters (from Moore 1978): Crown typically short, subglobular (exceptionally biconvex), with stoutly built cup well delimited from arms, with are composed of very low and wide brachials and free above radials, arms unbranched or with one to three isotomous bifurcations, their distal extremities curved inward to conceal tegmen and with or without clockwise torsion. Interbrachials generally lacking, but present in Nipterocrinidae. Infrabasals sloping upward and visible from side or forming flat base of cup with extension beyond stem impression, rarely in basal concavity, flat and down-sloping circlets not visible from side, normally with two large plates (AB, DE) and small one in C ray but solidly fused together in several genera. Basals relatively large, with surface area little smaller than large radials, which have straight or gently concave articular facets occupying entire width of plate or uncommonly only small part of it, facets short transversely, approximately equal to thickness of radials, and lacking well-defined ridge and ligament fossae. Radianal obliquely left beneath C radial and moderately large anal X above squarely truncate distal edge of CD basal, or lacking radianal. Arms composed of very wide short brachials, branching on primibrachs 2, secundibrachs 2 to 4, and higher in some genera. Stem mostly subcylindrical, composed of hetero- or homeomorphic low columnals with small axial canal, without cirri; stem may be distinctly xenomorphic and in forms with enrolled column moderately to strongly crescentic in shape.

Lecanocrinacea [Lecanocrinites]
    |--Gaulocrinus Kirk 1945 [Gaulocrinidae] M78
    |    `--*G. trautscholdi (Wachsmuth & Springer 1885) [=Stemmatocrinus trautscholdi] M78
    |--Palaeoholopodidae [Palaeoholopidae] M78
    |    |--Palaeoholopus Wanner 1916 M78
    |    |    `--*P. pretiosus Wanner 1916 M78
    |    `--Permobrachypus Moore & Strimple 1973 (see below for synonymy) M78
    |         `--*P. adhaerens (Wanner 1929) [=*Brachypus adhaerens] M78
    |--Edriocrinidae J18
    |    |--Lodanella Kayser 1885 J18, K67
    |    |    `--L. mira U78
    |    `--Edriocrinus Hall 1858 M78
    |         |--*E. pocilliformis Hall 1859 M78
    |         |--E. dispansus M78
    |         `--E. sacculus M78
    |--Prophyllocrinidae M78
    |    |--Ancistrocrinus Wanner 1924 M78
    |    |    `--*A. vermistriatus Wanner 1924 M78
    |    |--Proapsidocrinus Wanner 1924 M78
    |    |    `--*P. permicus Wanner 1924 M78
    |    `--Prophyllocrinus Wanner 1916 M78
    |         |--*P. dentatus Wanner 1916 M78
    |         `--P. cuspidatus Wanner 1916 M78
    |--Lecanocrinidae [Cyrtidocrinidae, Lecanocrininae] M78
    |    |--Mysticocrinus Springer 1918 M78
    |    |    `--*M. wilsoni Springer 1918 M78
    |    |--Miracrinus Bowsher 1953 M78
    |    |    `--*M. perdewi (Bowsher 1953) [=Lecanocrinus (Miracrinus) perdewi] M78
    |    |--Geroldicrinus Jaekel 1918 M78
    |    |    `--*G. roemeri (Schulze 1867) [=Lecanocrinus roemeri] M78
    |    `--Lecanocrinus Hall 1852 M78 [incl. Alsopocrinus Tansey 1924 EB01, Cyrtidocrinus Angelin 1878 M78]
    |         |--*L. macropetalus Hall 1852 M78
    |         |--*Alsopocrinus’ anna Tansey 1924 ML78
    |         |--L. facietatus (Angelin 1878) [=Cyrtidocrinus facietatus] M78
    |         `--L. pisiformis U78
    |--Calycocrinidae M78
    |    |--Plagiocrinus Wanner 1924 M78
    |    |    |--*P. torynocrinoides Wanner 1924 M78
    |    |    `--P. jaekeli M78
    |    |--Ammonicrinus Springer 1926 M78
    |    |    |--*A. wanneri Springer 1926 M78
    |    |    |--A. doliiformis U78
    |    |    `--A. sulcatus U78
    |    `--Calycocrinus Wanner 1916 M78
    |         |--*C. curvatus Wanner 1916 M78
    |         |    |--C. c. curvatus [=C. c. typus Wanner 1924] M78
    |         |    `--C. c. subturbinatus M78
    |         `--C. perplexus U78
    |--Nipterocrinidae M78
    |    |--Hormocrinus Springer 1920 M78
    |    |    `--*H. tennesseensis (Worthen 1890) [=Centrocrinus tennesseensis] M78
    |    |--Cholocrinus Springer 1906 M78
    |    |    `--*C. obesus (Angelin 1878) [=Forbesiocrinus obesus] M78
    |    |--Nipterocrinus Wachsmuth in Meek & Worthen 1868 M78
    |    |    |--*N. wachsmuthi Meek & Worthen 1868 M78
    |    |    `--N. arboreus M78
    |    `--Pycnosaccus Angelin 1878 [incl. Oncocrinus Bather 1890] M78
    |         |--*P. scrobiculatus (Hisinger 1840) [=Cyathocrinites scrobiculatus] M78
    |         |--P. bucephalus (Bather 1890) [=*Oncocrinus bucephalus] M78
    |         |--P. nodulosus M78
    |         |--P. patei M78
    |         `--P. tenuibrachiatus M78
    `--Mespilocrinidae M78
         |--Syntomocrinus Wanner 1916 M78
         |    `--*S. sundaicus Wanner 1916 M78
         |--Loxocrinus Wanner 1916 M78
         |    `--*L. globulus Wanner 1916 M78
         |--Petrocrinus Wanner 1924 M78
         |    `--*P. beyrichi Wanner 1924 M78
         |--Mespilocrinus de Koninck & Le Hon 1854 M78
         |    |--*M. forbesianus de Koninck & Le Hon 1854 M78
         |    `--M. konincki M78
         `--Cibolocrinus Weller 1909 M78
              |--*C. typus Weller 1909 M78
              |--C. banioni M78
              `--C. punctatus M78

Permobrachypus Moore & Strimple 1973 [=Brachypus Wanner 1929 nec von Meyer 1814 nec Swainson 1824 nec Meigen 1824 nec Schoenherr 1825 nec Gray 1825 nec Fitzinger 1826 nec Guilding 1828] M78

*Type species of generic name indicated

REFERENCES

[EB01] 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.

[J18] Jaekel, O. 1918. Phylogenie und System der Pelmatozoen. Paläontologische Zeitschrift 3: 1-128.

[K67] Kesling, R. V. 1967. Cystoids. In Treatise on Invertebrate Paleontology pt. S. Echinodermata 1. General characters. Homalozoa-Crinozoa (except Crinoidea) (R. C. Moore, ed.) vol. 1 pp. S85-S267. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).

[M78] 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).

[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).

[U78] Ubaghs, G. 1978. Skeletal morphology of fossil crinoids. In Treatise on Invertebrate Paleontology pt. T. Echinodermata 2. Crinoidea (R. C. Moore & C. Teichert, eds) vol. 1 pp. T58-T216. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

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