INVESTIGADORES
BOND mariano
congresos y reuniones científicas
Título:
NEW FINDINGS OF FOSSIL MAMMALS FROM THE EARLY MIOCENE CERRO BANDERA FORMATION (NEUQUÉN PROVINCE, ARGENTINA). BIOCHRONOLOGICAL AND PALEOBIOGEOGRAPHICAL CONSIDERATIONS
Autor/es:
KRAMARZ, A. , FORASIEPI, A., BOND, M., GARRIDO, A., ARNAL, M., AGUIRREZABALA, G AND L. FILIPPI
Lugar:
San Juan
Reunión:
Congreso; IV Congreso de Paleontología de Vertebrados; 2011
Institución organizadora:
Universidad Nacional de San Juan
Resumen:
NEW FINDINGS OF FOSSIL MAMMALS FROM THE EARLY MIOCENE CERRO BANDERA FORMATION (NEUQUÉN PROVINCE,ARGENTINA). BIOCHRONOLOGICAL AND PALEOBIOGEOGRAPHICAL CONSIDERATIONSA. KRAMARZ1,2, A. FORASIEPI1,3, M. BOND1,4, A. GARRIDO5, M. ARNAL1,2, G. AGUIRREZABALA4 and L. FILIPPI 61Consejo Nacional de Investigaciones Técnicas y Científicas (CONICET)2Museo?Bernardino Rivadavia?. Av. Angel Gallardo 470, 1405 CABA, Argentina3Museo de Historia Natural de San Rafael. Parque Mariano Moreno s/nro, 5600 San Rafael, Mendoza, Argentina4Museo de La Plata. Paseo del Bosque s/n, 1900 La Plata, Buenos Aires, Argentina5Museo ?Prof. Dr. Juan A. Olsacher?, Zapala, Neuquén, Argentina6Museo Carmen Funes, Av. Córdoba 55, 8318 Plaza Huincul, Neuquén, ArgentinaThe Cerro Bandera Formation is a Miocene continental succession exposed in isolated areas at the centre-East of Neuquén Province, NorthwesternPatagonia, Argentina (Leanza and Hugo, 1997). The sequence is 45 m thick, composed by primary and reworked pyroclastic depositsand scant sandstone levels, filling local paleovalleys excavated on Late Cretaceous and Paleocene rocks (Leanza and Hugo, 1997; Kramarzet al., 2005). Based upon its faunal content, this unit was referred to the Colhuehuapian SALMA (early Miocene) (Kramarz et al., 2005).Here we report a new mammal association derived from two new localities of the Cerro Bandera Formation situated at the northeastern slopeof the Barda Negra (Zapala Department). The specimens are housed at Museo ?Prof. Dr. Juan A. Olsacher?, Zapala. Mammals from Loc. A(39°0′06.3S?69°40′54.3″) come from whitish-greyish tuffaceous levels, about six meters from the base of the stratigraphic section exposedin the area. Those from Loc. B (39°02′26.21″S?69°40′53.36″W) derive from similar rocks located about 25 meters from the exposed base.In contrast to other previously studied localities (Kramarz et al., 2005), the new ones provided more abundant and more complete remains.Many of the taxa newly recorded in both localities support a Colhuehuapian age [e.g., Colpodon Burmeister, 1885 (Notoungulata)]. However,the same deposits also provided some few taxa that are not represented in the typical Colhuehuapian and younger mammal associationsfrom Central Patagonia, but in the immediately older Deseadan SALMA (late Oligocene) [e.g., Cephalomys Ameghino, 1897 (Rodentia),Archaeohyracidae (Ameghino, 1897) (Notoungulata)]. Although further studies and absolute datings are necessary, these new findings suggestthat the Cerro Bandera mammal assemblage would document the survival in northern Patagonia of some mammals that already becameextinct in central and southern Patagonia before the early Miocene. As an alternative interpretation, the Cerro Bandera assemblage wouldrepresent a transitional association between the typical Deseadan and Colhuehuapian faunas, corresponding to a pre-Colhuehuapian age,hitherto recorded anywhere else in South America.Ameghino, F. 1897. Mammifères crétacés de l´Argentine. Boletín Instituto Geográfico Argentino 18: 406?429, 431?521.Burmeister, H. 1885. Exámen crítico de los mamíferos y reptiles fósiles denominados por D. Augusto Bravard y mencionados en su obra precedente. Analesdel Museo Nacional de Buenos Aires 3: 95?174.Kramarz, A., Garrido, A., Forasiepi, A., Bond, M. and Tambussi, C. 2005. Estratigrafía y vertebrados (Mammalia ? Aves) de la Formación Cerro Bandera,Mioceno Temprano de la provincia del Neuquén, Argentina. Revista Geológica de Chile 32: 273?291.Leanza, H.A. and Hugo, C.A. 1997. Hoja geológica 3969-III Picun Leufú. Servicio Geológico Minero (SEGEMAR), Boletín 218: 1?135.