Hiscobeccus

Classification
Phylum: Brachiopoda
Class: Rhynchonellata
Order: Rhynchonellida
Family: Rhynchotrematidae
Genus: Hiscobeccus Amsden, 1983
Cincinnatian Species: Hiscobeccus capax

Taxonomic Details

Type species: Atrypa capax Conrad, 1842 (Jin et al., 1997; Jin & Zhan, 2001)

Geologic Range
Late Ordovician

Common Paleoecology
Hiscobeccus is an extinct genus of stationary epifaunal suspension feeders

Identification in Hand Sample:

  • Moderate to strong biconvexity
  • Moderately deep dorsal and ventral valves
  • Ventral beak moderately to strongly curved,often appressed to opposite umbo
  • Strongly formed costae and lamellose shells, shell outline varibly subovate
  • Dental plates typically absent to rudimentary, open delthyrium with no deltidial plates or rarely small, incipient plates

Geographic Occurrences

		

Published Description

Swisher (2009):

  • Moderate to strong biconvexity, moderatly deep dorsal and ventral valves. Ventral beak moderatly to strongly curved, often appressed to opposit umbo. Strongly formed costae and lamellose shells, shell outline varibly subovate; deeply impressed ventral muscle scars. Dental plates typically absent to rudimentary, open delthyrium with no deltidial plates or rarely small, incipient plates. Dorsal hinge plate thick, contains bladelike cardinal process, thickened septum. MOdefied from Amsden 1983 and Jinet al 1989, Jin and Lenz 1992.

Treatise on Invertebrate Paleontology, Part H, Vol. 4 (2002):

  • Subcircular outline and dorsibiconvex profile; lateral and anterior margins generally steep. Beak erect to incurved; delthyrium wide, deltidial plates absent or incipient. Fold and sulcus strong; anterior commissure uniplicate; tongue distinct, trapezoid, dentate. Costate strong, simple, angular, arising at beaks, dental plates rudimentary or fused to valve walls; ventral muscle field deeply impressed. Hinge plates thick; dorsal median septum long; cardinal process septiform

H. capax