Early Biogeographic History of Ostariophysan Fishes

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A theory is proposed for the early biogeographic history of ostariophysan fishes that incorporates: 1) the most recent data on geographic and geologic distribution of ostariophysans, 2) plate tectonic theory, 3) a phylogenetic hypothesis, including a consideration of Hennig-Brundin concepts of phylogenetic biogeography. The evidence suggests only three possible centers of origin for ostariophysans: 1) Africa, 2) South America or 3) Gondwana. If the origin of ostariophysans was a post-Jurassic event, then South America is the most likely center of origin for the group. We postulate that ostariophysans originated in South America in the earliest Cretaceous and there split into two sister groups, the Cypriniformes and Siluriformes. These groups dispersed throughout South America and the adjoining west shield area of Africa by middle Cretaceous. After regression of the west African epicontinental sea and rifting apart of west Africa and South America in the late Cretaceous, characoids and siluroids dispersed throughout Africa. In South America and Africa these groups underwent independent adaptive radiations.