Molecular evidence for species level divergence in African Nile Crocodiles Crocodylus niloticus (Laurenti, 1786)

Andreas SCHMITZ, Patrick MANSFELD, Evon HEKKALA, Tara SHINE, Hemmo NICKEL, George AMATO & Wolfgang BÖHME

en Comptes Rendus Palevol 2 (8) - Pages 703-712

Published on 31 December 2003

Relationships of the newly discovered dwarf crocodiles from Mauritania were inferred from mitochondrial 12S sequences. Specimens from 13 different Crocodylus niloticus populations (from East Africa, West Africa and Madagascar) were compared. Additional representatives of the genus Crocodylus (one from Africa and one from Australia), the African genus Osteolaemus and the South American alligatorid Paleosuchus palpebrosus (as outgroup) were included in the analysis. Maximum-likelihood and Bayesian analyses yielded relationships that were strikingly different from currently prevailing phylogenetic hypotheses. Both analyses consistently revealed two groups, one consisting of the monophyletic West- and Central African populations and the other of a paraphyletic group containing the East African and Madagascan populations. High genetic divergence between those groups indicates separation on the species level. Furthermore 'C' cataphractus is clearly shown not to be a member of the genus Crocodylus. The resulting nomenclatural changes are discussed.


Crocodylus, C. niloticus, C. suchus, Mecistops, 12S mtDNA, maximum-likelihood, bayesian analysis, taxonomy

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