Dinichthys, HERZERI NEWBERRY, 1868

Carr, Robert K. & Hlavin, William J., 2010, Two new species of Dunkleosteus Lehman, 1956, from the Ohio Shale Formation (USA, Famennian) and the Kettle Point Formation (Canada, Upper Devonian), and a cladistic analysis of the Eubrachythoraci (Placodermi, Arthrodira), Zoological Journal of the Linnean Society 159 (1), pp. 195-222 : 198

DINICHTHYS HERZERI NEWBERRY, 1868 ( FIG. 1 )

Diagnosis (emended from Newberry, 1868): A Dinichthys species with an inferognathal characterized by the combination of two anterior cusps, and a denticulate posterior occlusal surface (comprising ~45% of the total length of the inferognathal). There are between ten and 14 adsymphysial denticles along the mesial surface of the anterior cusp. The anterior superognathal possesses a lateral cusp with a dorsal– ventral-oriented row of denticles along the lateral surface of the cusp. Posterior to the lateral cusp, the lateral face of the anterior superognathal is enclosed. At the base of the enclosed surface there is an obtuse occlusal surface forming an anterior step along the lateral face. The posterior superognathal possesses lateral and posterior rows of denticles. On the nuchal plate there are large paired fossae adjacent to the posterior process of the nuchal plate that open posteriorly.

Holotype: AMNH 81 ( Fig. 1A ), an incomplete skull roof consisting of a nuchal plate and other indeterminate dermal plates, a right inferognathal, and a posterior superognathal.

Figures

Figure 1. Dinichthys herzeri. A, AMNH 81 (holotype), incomplete nuchal plate in internal view. B, AMNH 73 (paratype), left inferognathal plate in lateral view. C, AMNH 34, left anterior superognathal in lateral view. D, AMNH 33, right posterior superognathal in lateral view. Reconstruction of six denticles in the posterior tooth row based on CMNH 7257. Drawings reproduced from Hlavin, 1976. Scale bars equal 3 cm.