Cope, Proc. Am. Phil. Soc., p. 573, Feb. 3, 1877 (Pal. Bull. 24).
Baur, Beiträge zur Morphogenie des Carpus und Tarsus der Vertebraten, I Theil, p. 16, 1888.
Cope, Trans. Am. Phil. Soc., XVI, p. 289, fig. 1, 1888.
Moodie, Science, n. s., XLI, No. 1044, p. 34, 1915.
Moodie, Am. Jour. Sci., XXXIX, pp. 509-512, fig. 2, May, 1915.
Type: Ichthycanthus ohiensis Cope.
The generic characters are derived from the characters presented by the posterior dorsal and caudal vertebræ, with adjacent parts. The posterior limbs are well developed, with distinct tibia and fibula, osseous tarsus, and 5 digits. Ribs elongate, simple, curved. Abdominal armature consisting of bristle-like rods in anteriorly directed chevrons. Dorsal vertebræ not elongate, with simple neural spines. Tail large, its vertebræ ossified, and furnished with slender chevron bones which terminate in a hæmal spine. Neural spines broad and directed backwards; the caudal series somewhat resembling that of a fish. All the centra are amphicœlous.
This genus differs from all those with enlarged and sculptured neural spines, and from those with abdominal scutes. It is equally distinct from those without ribs, abdominal rods, or limbs. It is possible that some of the species referred to Tuditanus, in which these parts are unknown, may belong to it, or that it may be established on a small species of Leptophractus, a genus known only as yet from the skull. With our present imperfect knowledge of the Linton forms it seems best to refer I. ohiensis and I. platypus to this distinct genus, Ichthycanthus.
Ichthycanthus ohiensis Cope.
Cope, Proc. Am. Phil. Soc., 1877, p. 573 (Pal. Bull. 24).