You'd think that if scientists were to discover a new species, it would be in some remote, uncharted tropical forest, not a laboratory in New York. But a team from the Sackler Institute for Comparative Genomics at the American Museum of Natural History has done the unexpected. Looking at the genes of the African dwarf crocodile, researchers found that the groupgenetically speakingcomprises three distinct species rather than one. This not only ends a long debate about the taxonomy of this group, previously thought to consist of two closely related subspecies, but also defines a new, distinct species from genetic samples.
"In the past, the two morphologically distinct crocodile populations were believed to be different genera, then later different species, and then finally different subspecies," explains first-author Mitchell Eaton. Eaton conducted the research at the Sackler Institute and is finishing his doctoral degree at the University of Colorado. "We collected samples in Africa to explore this taxonomic question, and we found a great deal of evolutionary divergence between populations in the Congo Basin and on the west coast of Central Africa. We alsoquite unexpectedlyfound a completely new species from far West Africa; there may be even more species that we haven't sampled yet!"
African dwarf crocodiles, genus Osteolaemus, live in the tropical forests of Central and West Africa. Adults typically grow to no more than 5 feet in length and are the smallest living members of the crocodilian family. The three groups identified in this current research include a species from the Congo Basin (O. osborni), another from Central Africa's Ogoou Basin (O. tetraspis), and the new, yet unnamed species from West Africa. All of these crocodiles look very similar, and all are widely hunted by local people as a source of food. In fact, these animals provide up to a quarter of the non-fish bush meat consumed in some areas of Centra
|Contact: Kristin Elise Phillips|
American Museum of Natural History