Preliminary phylogenetic analysis of otters (Carnivora: Mustelidae) combining morphology and molecular data

PREVOSTI, F. J.; CHEMISQUY, M. A.

San Javier, Tucumán, Argentina

Jornada; XXVII Meeting of the Willi Hennig Society y VIII Reunión Argentina de Cladística y Biogeografía; 2008

Willi Hennig Society

The otters are a group of aquatic carnivores that appear in the Miocene and in the present are represented by 13 species, which inhabit all continents, except Antarctica and Oceania. The Lutrinae are deeply nested in the Mustelidae, and recent DNA studies show that are the sister taxa of the genus Mustela. Previous phylogenetic analysis of this subfamily showed three main clades: 1) Pteronura; 2) Lontra; 3) Aonyx + Lutra+ Enhydra + Lutrogale + Hydrictis. Those studies are based in mitochondrial and nuclear DNA, without including other sources of phylogenetic characters, like ostelogical and soft anatomy. Thus it is not possible to include the numerous taxa known from the rich fossil record of the group. In this contribution we present a preliminary analysis based on cranial, dental and postcranial characters, and their combination with nuclear and mitochondrial DNA sequences, of all the living otters plus some fossils, and several outgroups. Our preliminary results show high incongruence between morphological and DNA partitions. The morphological matrix support the monophyly of Lutrinae as the sister clade of Mustela+Galictis. Amblonyx is the most basal taxa inside Lutrinae and the others are grouped in two clades: (Lontra + Lutra)) and ((Lutrogale +Pteronura)(Aonyx + Enhydra)). The fossils Satherium and Enhydritherium are grouped with Enhydra lutris and Pteronura brasiliensis, respectively, but Mionictis is placed outside the clade Lutrinae + (Mustela+Galictis). The combined philogeny with equal weight shows a monophyletic Lutrinae but with low resolution, and only with a few small clades solved (e.g. Lontra; Satherium+Pteronura). With implied weighting we obtain the clades recognized in the published DNA studies, but several with very low branch supports. These low resolution and/or low support values are generated by two fossils (i.e. Aonyx aonychoides, Mionictis) and a living species (Aonyx congica) without DNA data. Beyond these, the position of the fossils agree with the expected by early authors in most of the cases.