Late Cretaceous bichirs from Madagascar provide the first documentation of Polypteriformes (Actinopterygii, Cladistia) in eastern Gondwana

Fossil polypterid elements have been recovered from the Upper Cretaceous (Maastrichtian) Maevarano Formation of Madagascar. These elements document the first known occurrence of polypterids outside of Western Gondwana, demonstrating that these fishes had a much more extensive biogeographic range in the Cretaceous than previously known. Although polypterids are currently confined to the fresh waters of Africa, fossil remains previously documented their presence in South America as well; these two continents formed Western Gondwana prior to their separation in the Early Cretaceous. The discovery of polypterid remains in Madagascar indicate that these fishes were more widely spread across Gondwana in the Mesozoic than previously recorded, reaching into areas of Eastern Gondwana. The new fossils likely represent new taxa based on their geographic distribution and indicate that an apparent peak of species richness among polypterids in the early Late Cretaceous may be, at least in part, a reflection of a lack of data from the fossil record, rather than a lack of diversity within the lineage.