The only previously known material of “Ceratodus” iheringi Ameghino, 1898 (the hoiotype, a tooth píate) was collected by Carlos Ameghino along with other marine and freshwater fossils in the “Piso Shehuenense” in Pari Aike, Río Shehuen, Southern Patagonia. The material was figured but not described. Fortunately, the hoiotype was preserved in the Museo de La Plata.
The bearing beds are presently included in the Mata Amarilla Formation which is considered Cenomanian-Coniasian in age. Additional lungfish material from the Southern part of Mendoza and Río Negro provinces was erroneously reponed by several authors to this species.In the present contribution, based on about 200 complete and fragmentary tooth plates from the type locality, we describe and diagnose the species “Ceratodus ” iheringi and a new genus, Atlantoceratodus.
The species appears to be only known in the type area. Atlantoceratodus iheringi most closely resembles “Ceratodus " madagascariensis Priem, 1924 from the upper Cretaceous (Campanian) of Madagascar and we suggest that both species pertain to the same genus.Facultad de Ciencias Naturales y Muse
