Martín de los Reyes

The Scelidotheriine Proscelidodon (Xenarthra: Mylodontidae) from the Late Miocene of Maimará (Northwestern Argentina, Jujuy Province)

1Dpto. de Paleontología, Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA), CCT–CONICET–Mendoza, Avda.Ruiz Leal s/n, Parque Gral. San Martín, 5500 Mendoza, Argentina. fpujos@mendoza-conicet.gov.ar 2Institut Français d’Etudes Andines, Casilla 18-1217, Av. Arequipa 4500, Lima 18, Peru. fpujos@yahoo.fr 3CONICET, División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, B1900FWA La Plata, Argentina. acandela@fcnym.unlp.edu.ar, regui@fcnym.unlp.edu.ar 4Facultad de Ingeniería, Universidad Nacional de Salta, Salta, Argentina. claudiagalli@fibertel.com.ar 5CONICET, Instituto de Geología y Minería, Universidad Nacional de Jujuy, 4600 San Salvador de Jujuy, Argentina. bcoira2004@yahoo.com.ar 6Facultad de Ciencias Naturales y Museo de La Plata, Paseo del Bosque, B1900FWA La Plata, Argentina. delossreyes@yahoo.com.ar 7Laboratorio de Sistemática y Biología Evolutiva (LASBE), Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, Argentina. mabello@ fcnym.unlp.edu.ar AMEGHINIANA 2012 Tomo 00 (0): xxx – xxx ISSN 0002-7014

Primer registro del género Jenynsia Günther, 1866 (Teleostei: Cyprinodontiformes) en el Pleistoceno Medio tardío de la provincia de Buenos Aires (Argentina)

En este trabajo se da a conocer un premaxilar izquierdo referible al genero Jenynsia recuperado en facies lacustres correspondientes al Piso-Edad Bonaerense (Pleistoceno Medio tardio) de la localidad de Centinela del Mar, provincia de Buenos Aires, Argentina. Dicho material constituye el primer registro fosil para este genero y uno de los escasos antecedentes para la familia Anablepidae. El hallazgo aqui comunicado brinda nuevas evidencias para la comprension de las ictiofaunas cuaternarias de America del Sur.

First Neogene skulls of Doedicurinae (Xenarthra, Glyptodontidae): morphology and phylogenetic implications

Among Glyptodontidae, Doedicurinae (late Miocene–early Holocene) includes the glyptodonts with the largest size and latest records. Doedicurinae is mainly characterised by a smooth surface of the osteoderms with large foramina, and a particular morphology of the caudal tube. All taxa except one (Doedicurus clavicaudatus) have been recognised and characterised on the basis of remains of caudal tubes and/or dorsal carapaces. This situation produced an evident overestimation of the real diversity of this group, and a taxonomic revision is needed. In fact, no Neogene skulls were known. We present and describe the first two Neogene skulls belonging to Doedicurinae (cf. Eleutherocercus antiquus). The materials come from the El Polvorín and Chapadmalal Formations, in the surroundings of Olavarría and Mar del Plata localities, respectively (Buenos Aires province, Argentina). A cladistic analysis was carried out in order to situate these materials among Glyptodontidae and inferring new synapomorphies at skull level in Doedicurinae. Cf. Eleutherocercus antiquus clusters with the Pleistocene species Doedicurus clavicaudatus showing three unambiguous synapomorphies, which in turn represents the first skull synapomorphies for Doedicurinae. Finally, the presence of cf. Eleutherocercus antiquus in the El Polvorín and Chapadmalal Formations suggests that the stratigraphic distribution of this species could include the Montehermosan–Chapadmalalan interval.

First evidence of scavenging of a Glyptodont (Mammalia, Glyptodontidae) from the Pliocene of the Pampean region (Argentina): taphonomic and paleoecological remarks

The Cingulata Glyptodontidae (Xenarthra) are one of the most conspicuous Cenozoic herbivore clades in South America reaching North America during the Great American Biotic Interchange. The evidence of predation on these large armoured mammals is very scarce and limited to a Pliocene skull (Glyptotherium) in North America and some latest Pleistocene-early Holocene specimens in South America, with signals of human consumption. In this contribution, we present the first case of scavenging on a glyptodont belonging to cf. Eosclerocalyptus lineatus (Hoplophorini) from the Pliocene of the Pampean region (Argentina). In addition, we analyze the potential scavengers and the paleoenvironmental context in which this occurred. The evidence suggests that: a) the carcass was covered by a shallow water body, probably an abandoned channel; b) the carcass was completely covered during a brief lapse of time, probably less than a year; c) the morphology of the bite marks clearly coincide with the dentition of the procyonid Chapalmalania (Mammalia, Procyonidae), thus corroborating some presumptions about the paleoautoecological trends of this taxon. Martín de los Reyes. Facultad de Ciencias Naturales y Museo de La Plata. Paseo del Bosque s/n (1900), La Plata, Buenos Aires, Argentina delossreyes@yahoo.com.ar Daniel Poiré. CIG de Investigaciones Geológicas, UNLP-CONICET, Calle 1 No 644, 1900 La Plata, Argentina dpoire@gmail.com Leopoldo Soibelzon. División Paleontología de Vertebrados, Facultad de Ciencias Naturales y Museo (UNLP). Paseo del Bosque s/n, 1900, La Plata, Buenos Aires, Argentina lsoibelzon@fcnym.unlp.edu.ar Alfredo E. Zurita. Centro de Ecología Aplicada del Litoral (CECOAL-CONICET) y Universidad Nacional del Nordeste. Ruta 5, km. 2,5, 3400, CC 128 Corrientes, Argentina azurita@cecoal.com.ar M.J. Arrouy. CIG de Investigaciones Geológicas, UNLP-CONICET, Calle 1 No 644, 1900 La Plata, Argentina marouy@gmail.com

First fossil records of silversides (Teleostei: Atheriniformes) from the Middle Pleistocene of Buenos Aires province, Argentina

First fossil records of silversides (Teleostei: Atheriniformes) from the Middle Pleistocene of Buenos Aires province, Argentina. This paper presents the fossil remains of silversides recovered in sedimentary sequences corresponding to Centinela del Mar district Bonaerian Stage-Age (Middle Pleistocene), Buenos Aires province, Argentina. The few only previously described fossil silversides are restricted to three Chilean and Argentinean Miocene localities. The silversides studied here present several diagnostic osteological characters that allow us to refer the remains to the genus Odontesthes. These records give us new data on the composition of the pleistocenic ictiofaunas of Argentina, besides representing the first fossil records of silversides from the Pampean region.

New material of Equus (Amerhippus) neogeus (Mammalia, Perissodactyla) from the late Pleistocene of Olavarría (Argentina)

This work has been made possible thanks to Research Project DGICYT CGL2010-19116/BOS and AECID Projects A/023681/09 and A/030111/10, Spain; and the Universidad Nacional del Centro de la Provincia de Buenos Aires, CONICET and projects ANPCYT PICT 07-01563 and PICT 11-0561.