New sarcopterygians from the carboniferous poti formation and from the permian rio do rasto formation, Brazil

Abstract

A new material of sarcopterygian fishes from the Mississippian of the Poti Formation and the Lopingian of the Rio do Rasto Formation are described here. The specimens consist of isolated scales, which show numerous thin and parallel growth lines, a pattern of ornamentation usually found in actinistians, differing from the Westoll-lines present in dipnoans. A precise identification of this new material was not possible, because the scales lack more accurate diagnostic features. The Mississippian occurrence spreads the distribution of coelacanthiforms in the Brazilian Paleozoic, which was restricted to the Permian. This material represents the oldest actinistian record in Brazil and the first Mississippian report of this group from South America. The occurrences from the Rio do Rasto Formation seems to have freshwater affinities, which was inferred by the depositional environment and associated biota. All these new data are important to the comprehension of coelacanths paleogeographical distribution during the Paleozoic in South America.