PHYLOGENETIC POSITION OF THE LARGE SOUTH AMERICAN FÓSIL CANIDS (CARNIVORA, CANIDAE): FOSSILS, MOLECULES AND LONG BRANCHES

PREVOSTI, FRANCISCO J.

La Plata

Jornada; Reunión de Comunicaciones Científicas en Homenaje al Dr. Rosendo Pascual, con motivo de sus 80 años; 2005

In the last ten years canid phylogeny has become clearer with the aid of morphological, ethological and molecular data from fossil and recent specimens, but these analysis have not included the large South American fossil canids. In order to clarify the position of these taxa in the context of the new studies, I constructed a matrix of 103 cranial and dental characters for 24 taxa and performed a phylogenetic analysis using maximum parsimony. Molecular, ethological and other data types from bibliographical sources were added to this matrix for a simultaneous analysis. The result clusters the fossils Theriodictis Mercerat 1891 + Protocyon Giebel 1855 (including “Canis” gezi Kraglievich 1928 as sister taxon of T. platensis Mercerat 1891) as sister group of Lycaon Brookes 1827, while C. dirus Leidy 1858+C. nehringi (Ameghino 1902) are the sister group of C. lupus Linnaeus 1758. The position of Theriodictis + Protocyon as sister taxon of Lycaon is sustained by characters associated with hypercarnivory. The molecular data support a clade formed by Speothos Lund 1839+ Ch. brachyurus (Illiger 1815) as sister taxa, but this group could represent an artefact known as “long branch attraction”, because the exclusion of one of these taxa alters the position of the other. These changes alter the position of the Protocyon + Theriodictis clade, which are sometimes clustered in a clade with other South American canids. Wider taxonomic sampling and the addition of other character sources could allow to assess the existence of this bias and the effect of convergences in the position of these fossil canids. PICT 8395.