Cahabagnathus Bergström, 1983

Zhen, Yong Yi, 2011, Middle to Late Ordovician (Darriwilian-Sandbian) Conodonts from the Dawangou Section, Kalpin Area of the Tarim Basin, Northwestern China, Records of the Australian Museum 63 (3), pp. 203-266 : 216-218

Cahabagnathus Bergström, 1983

Petalognathus Drygant, 1974b (a junior homonym of Petalognathus Duméril & Bibron, 1854 , a reptile, see Clark et al., 1981, p. W129).

Type species. Polyplacognathus sweeti Bergström, 1971 .

Remarks. Eight species belonging to Cahabagnathus are known in the literature, ranging in age from the early P. serra Zone to early A. tvaerensis Zone. Seven of these (the exception being C. sweeti ) are recorded only from Laurentia, primarily in warm, shallow water facies (Leslie & Lehnert, 2005, Table 1). Leslie & Lehnert (2005) indicated that episodes of wider dispersals of this genus, dominated by endemic species and centered in Laurentia, were associated with major sea level transgressions. Cahabagnathus sweeti represents the acme of the cahabagnathid development at or near the Middle/Late Ordovician transition, when it became more cosmopolitan and also invaded deeper and cooler water environments.