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Mar del Plata, Argentina

Quinteros A.S.,Catedra de Anatomia Comparada
Herpetologica | Year: 2012

Liolaemus alticolor is redescribed herein, providing new character states that distinguish this taxon from all other members of the alticolorbibronii group. Two new species of the alticolorbibronii group are also described. One of the new species occurs in northern Argentina, in the Jujuy Province, whereas the other occurs in southern Argentina, in the Neuqun Province (northern Patagonia). Both of them exhibit characters that distinguish them from each other and from all other members of the alticolorbibronii group. A key to the species of this group is provided. © 2012 by The Herpetologists' League, Inc.

Fernandez F.J.,Catedra de Anatomia Comparada | Fernandez F.J.,CONICET | De Santis L.J.M.,Catedra de Anatomia Comparada | Neme G.A.,CONICET
Archaeofauna | Year: 2015

Micromammal remains from the archaeological sequence of Arroyo Malo-3 (AMA-3,34°51′18"S, 69°53′00"W; soutwestem Mendoza, Argentina) are taxonomically identified, and taphonomic and paleoenvironmental conditions assessed. Small mammal remains (NISP = 7239, MNE= 7211, MNI = 730) were recovered from Holocene temporal units (Unit IH = 8900-3810 years 14C BP; Unit H = 3810-2200 years 14C BP; Unit I = 2200-∼100 years 14C BP). The taphonomic evidences such as pellets preserved in the stratigraphy, mostly moderate but also high digestive marks on teeth and postcraneal bones, and relative abundance patterns of skeletary parts, indicate that the main accumulating agents of the micromammal assemblages recovered from the units of AMA-3 would have been the Accipitriformes, possibly Geranoaetus melanoleucus (black-chested buzzard-eagle) or Buteo polyosoma (red-backed hawk). The scarce record of weathered bones, the absence of trampling marks, roots, sediment corrosion and water transport and the discovery of numerous specimens with manganese oxide impressions suggest that the remains had a rapid burial and good preservation, although with high moisture levels. The micromammal assemblages of AMA-3 showed a remarkable taxonomic stability, with some minor changes towards the Late Holocene. The major changes occurred in the recent micromammal assemblages close to the site, marked by an increase of shrubs attributable to human impact possibly produced by domestic livestock reinforced in the south of Mendoza since the 19th century. The paleoenvironmental and taphonomical information presented provides a relevant framework to improve archaeological studies of the biogeography and subsistence system of southern Mendoza hunter-gatherer populations during the Holocene.

The musculature of the hindlimb of the cursorial caviomorph Dasyprocta azarae is described and functionally evaluated, together with osteological associated traits. Our results show that several features are indicative of emphasized parasagittal movements and stabilized joints. Mm. glutei are relatively well developed, in agreement with an enhanced extension of the hip joint. The relative elongation of the ischium indicates an improved mechanical advantage of the hamstring muscles, required for powerful extension of the hip. M. iliopsoas would act mainly as a protractor of the femur rather than as a rotator. M. peroneus brevis, an evertor and plantarflexor of the foot, is absent. The inversion of the pes would be reduced, such as expressed by the marked reduction of the m. tibialis caudalis. Osteological characters are arranged to facilitate parasagittal movements and to restrict joint mobility. Some features of Dasyprocta (e.g., presence of a gluteal tongue of m. gluteus medius, reduction in number of m. lumbricales, presence of a gluteal crest of the ilium) are interpreted as potential synapomorphies of cavioids. Other features associated to cursoriality (absence of mm. peroneus brevis, reduction of m. tibialis caudalis) would have been acquired independently in the extreme cursorial cavioids Dasyprocta and Dolichotis. © 2010 by Walter de Gruyter - Berlin - New York.

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