Papers by M. Teresa.alberdi.alonso.10866
Revista del Museo Argentino de Ciencias Naturales, Nueva Serie
First records of the equid Hippidion (Perissodactyla) in the Pleistocene of Mendoza province, Arg... more First records of the equid Hippidion (Perissodactyla) in the Pleistocene of Mendoza province, Argentina. We report the first records of the horse Hippidion in Mendoza province (Argentina). They come from two different localities, Uspallata and El Carrizal, both located near the city of Mendoza. The fossils from Uspallata consist of dental elements of a single, young adult individual (16 incisor-canine fragments, right P2-M2, left P2-M1 and fragments of left M3, right lower p2-p3, and left lower p3), stored at the Museo de Ciencias Naturales y Antropológicas J. C. Moyano in Mendoza (MCNAM-PV 3808). They were found at the northwestern extreme of the Cordón del Plata, southern Uspallata valley, in the Cordillera Frontal. Remains appeared in silt-sandy levels of an impounding paleo-lake generated from the Piedras Blancas rock avalanche. Stratigraphic studies carried out in this region indicate both, rock avalanche and lake deposits, are late Pliocene-Middle Pleistocene in age, because overlying ash levels could be correlated by geochemistry analyses with another close ash layers previously dated by Ar 39 /Ar 40 method 350±80 Ky. In turn, the presence of an equid states a maximum age younger than 2.5 Ma, or late Pliocene. The specimen from El Carrizal is a well-preserved first central phalange, found by local people in the sourroundings of El Carrizal dam, about 70 km south of Mendoza city. Morphological features (oval protocone, rounded protoconid and hypoconid, reduced metaconid-metastylid double knot) allow the teeth from Uspallata to be ascribed to the genus Hippidion Owen. Similarly, the phalange (1FIII) from El Carrizal presents the morphology of this genus (strong muscular insertions), in contrast to the genus Equus (Amerhippus) Hoffstetter. Species of Hippidion are mainly differentiated by the leg bones, the dentition being very homogeneous and just showing differences in size. Even though postcranial remains would allow a fully reliable determination, the tooth size and hipsodonty of the Uspallata specimen, as well as its stratigraphic origin (older than late Pleistocene), supports its determination as H. devillei (Gervais). At the same time, the morphology and dimensions of the phalange also support its ascription to this species. Hippidion devillei has been found in Jujuy, San Luis, and Buenos Aires provinces. Its presence in Mendoza supports a space-temporal distribution in a North-Southeast way during the latest Pliocene or early-middle Pleistocene.
A detailed study has been undertaken with an unique horse bone deposit at Cedral, San Luis Potosí... more A detailed study has been undertaken with an unique horse bone deposit at Cedral, San Luis Potosí, central Mexico. Morphological and morphometrical characters are used, as well as bivariate and multivariate statistics for both cranial and postcranial elements, and additional data incorporated for specimens from other Pleistocene
Mexican localities. Measurements for most of the studied materials are provided, as well as estimates of body mass for each species. Three species are represented in several Mexican late Pleistocene deposits, coincident with the Rancholabrean Land Mammal Age. All three may have been contemporaneous: a large-sized horse Equus mexicanus Hibbard, 1955 known from the western USA throughout Mexico and Central America; a widespread medium-sized horse Equus conversidens Owen, 1869 occurring in most of North and Central America; and a new small-sized horse Equus cedralensis sp. nov., presently known only from Mexican localities. Recognizing the co-occurrence of three late Pleistocene horse species (genus Equus sp.) in Mexico is important for understanding the diversity and extinction patterns at the time of the
early presence of humans in the continent. Additionally, environmental inferences are proposed, but further research is warranted to test those.
Proceedings of the National Academy of Sciences, 2009
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Papers by M. Teresa.alberdi.alonso.10866
Mexican localities. Measurements for most of the studied materials are provided, as well as estimates of body mass for each species. Three species are represented in several Mexican late Pleistocene deposits, coincident with the Rancholabrean Land Mammal Age. All three may have been contemporaneous: a large-sized horse Equus mexicanus Hibbard, 1955 known from the western USA throughout Mexico and Central America; a widespread medium-sized horse Equus conversidens Owen, 1869 occurring in most of North and Central America; and a new small-sized horse Equus cedralensis sp. nov., presently known only from Mexican localities. Recognizing the co-occurrence of three late Pleistocene horse species (genus Equus sp.) in Mexico is important for understanding the diversity and extinction patterns at the time of the
early presence of humans in the continent. Additionally, environmental inferences are proposed, but further research is warranted to test those.
Mexican localities. Measurements for most of the studied materials are provided, as well as estimates of body mass for each species. Three species are represented in several Mexican late Pleistocene deposits, coincident with the Rancholabrean Land Mammal Age. All three may have been contemporaneous: a large-sized horse Equus mexicanus Hibbard, 1955 known from the western USA throughout Mexico and Central America; a widespread medium-sized horse Equus conversidens Owen, 1869 occurring in most of North and Central America; and a new small-sized horse Equus cedralensis sp. nov., presently known only from Mexican localities. Recognizing the co-occurrence of three late Pleistocene horse species (genus Equus sp.) in Mexico is important for understanding the diversity and extinction patterns at the time of the
early presence of humans in the continent. Additionally, environmental inferences are proposed, but further research is warranted to test those.