. Atlantoceratodus, a new genus of lungfish from the upper Cretaceous of South America and Africa

CIONE, ALBERTO; GOUIRIC, S; GOIN, FRANCISCO; POIRE, DANIEL G.

Revista del Museo de La Plata

Museo de La Plata

Lugar: La Plata; Año: 2007 vol. 10 p. 1 - 12

0372-4565

Abstract Studies on fossil freshwater fishes from southern South America began at the end of the XIX century with the discovering of the dipnoan "Ceratodus"  iheringi along with Lepidotes-like teeth by Florentino Ameghino. The only known material of "Ceratodus" iheringi (the holotype) was collected by Carlos Ameghino with many other marine and freshwater fishes in the "Piso Shehuenense" in Pari Aike, Río Shehuen, southern Patagonia. The material was figured but not described. The bearing beds are presently included in the Mata Amarilla Formation which is considered Coniasian in age. Until now, they are the oldest dipnoans known in southern South America. Additional lungfish material putatively pertaining to this species was later reported from the southern part of Mendoza and Río Negro by several authors. In the present contribution, based on more than 200 tooth plates from the type locality, we describe and diagnose the species "Ceratodus" iheringi (Ameghino, 1898). We find that it is a valid species which is only known in the type locality.  We discuss the relation of "Ceratodus" iheringi with the ptychoceratodontids. "C." iheringi most closely resembles "C." madagascariensis (Priem, 1924) from the upper Cretaceous (Campanian) of Madagascar. Ceratodontids previously described from the late Campanian-early Maastrichtian Los Alamitos Formation and La Colonia Formation of northern Patagonia correspond to a species of the Australian genus Metaceratodus. Consequently, during the early late Cretaceous, Patagonian dipnoans were related with those of Africa but during the Campanian-Maastrichtian, they appear to have been related to Australian ones.