A new species of Hathliacynidae (Metatheria, Sparassodonta) from the Middle Miocene of Quebrada Honda, Bolivia

FORASIEPI AM; SANCHEZ-VILLAGRA M; GOIN FJ; TAKAI M; SHIGEHARA N; KAY RF

JOURNAL OF VERTEBRATE PALEONTOLOGY

Society of Vertebrate Paleontology

Lugar: Lawrence; Año: 2006 vol. 26 p. 670 - 684

0272-4634

We describe a new species of Hathliacynidae (Sparassodonta, Metatheria), Acyon myctoderos from the middle Miocene of Quebrada Honda, Bolivia. This new species is the largest known hathliacynid. Differences with the type species of the genus, A. tricuspidatus, include: longer diastemata among premolars; p2 comparatively more robust, with a better developed posterior cusp and with a sharp anterior crest; lower molars with less developed anterobasal cingulum; m1-3 with the hypoconulids less salient posteriorly and more vertically oriented; and larger hypoconids at least on the m2. After a phylogenetic analysis among nine Sparassodonta taxa, and with Mayulestes as out-group, we conclude that the genus Acyon is more closely related to Cladosictis than to any other hathliacynid.