Abstract

URRUTIA, Juan J.; MONTALVO, Claudia I.  and  SCILLATO-YANE, Gustavo J.. Dasypodidae (Xenarthra, Cingulata) from the Cerro Azul Formation (late Miocene) of La Pampa province, Argentina. Ameghiniana [online]. 2008, vol.45, n.2, pp.289-302. ISSN 1851-8044.

A total of 5,185 fossil remains of dasypodids were recovered from 20 outcrops of Huayquerian age (late Miocene) of the Cerro Azul Formation in La Pampa (Argentina). Sixteen taxa were recorded, all belonging in the Subfamily Euphractinae: Chasicotatus ameghinoi Scillato-Yané, Chasicotatus sp., Doellotatus inornatus (Rovereto), Doellotatus chapadmalensis Bordas, Ringueletia simpsoni (Bordas), Chorobates villosissimus (Rovereto), Chorobates cf. C. villosissimus, Macroeuphractus morenoi (Lydekker), M. retusus Ameghino, Macroeuphractus sp., Vetelia perforata Scillato-Yané, Macrochorobates scalabrinii (Moreno y Mercerat), Macrochorobates chapalmalensis (Ameghino), Proeuphractus limpidus Ameghino, Proeuphractus sp. and Euphractini incertae sedis. M. chapalmalensis, P. limpidus and Euphractini incertae sedis are first records from the Cerro Azul Formation. The range of M. chapalmalensis reaches down to the Huayquerian. Compositional variation of the dasypodid fauna among the surveyed outcrops are believed to be due mainly to temporal differences. The relative position of some of the localities was adjusted within a biostratigraphic frame previously proposed for the Cerro Azul Formation. The dasypodid association of the Cerro Azul Formation shows similarity with other Miocene and Pliocene faunas from central and north-western Argentina. However, those localities where associations hinting younger ages show faunal compositions increasingly similar to those contained in Neogene formations exposed along the coast of Buenos Aires province.

Keywords : Dasypodids; Systematics; Biostratigraphy; Late Miocene; La Pampa; Argentina.