Browsing by Author "Villavicencio, Natalia"

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    First record of cf. Aenocyon dirus (Leidy, 1858) (Carnivora, Canidae), from the Upper Pleistocene of the Atacama Desert, northern Chile
    (2022) Caro, Francisco J.; Labarca, Rafael; Prevosti, Francisco J.; Villavicencio, Natalia; Jarpa, Gabriela M.; Herrera, Katherine A.; Correa-Lau, Jacqueline; Latorre, Claudio; Santoro, Calogero M.
    Fossil records of canids are rare and incomplete in South America. In Chile, all well-identified taxa are part of the "South American Canid Clade" and come from sites located in southern Patagonia. Here, we report the first record for Chile of a taxon of the "Canis clade," assigned to cf. Aenocyon dirus. The fossil remains consist of a partially complete left hind limb, exposed by aeolian deflation, which facilitated its discovery at an isolated setting in Quebrada Mani, named QM38 site, in the southern sector of the Pampa del Tamarugal basin, part of the hyperarid core of the Atacama Desert, northern Chile. Measurements of the fossil are larger than the Protocyon troglodytes, falling in the smaller size range of A. dirus and within the larger range of Theriodictis platensis. Its morphological features compared with bone references of large extinct canids show that the fossil belongs to a small-sized Aenocyon. The remains occur in surface silty clays deposited by an alluvial fan that was active in the Pampa del Tamarugal basin in the Late Pleistocene. A radiocarbon date from bone apatite yielded an age of 14,660 cal years BP, placing it within the first half of the Central Andean Pluvial Event when this basin was wetter, well vegetated, and inhabited by large, medium, and small herbivores. No other large predator records are known from this basin, and our find affords a more complete view of this ecosystem which thrived in the hyperarid core of the Atacama during the Late Pleistocene.
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    The extinct Notiomastodon platensis (proboscidea, Gomphoteriidae) inhabited mediterranean ecosystems during the Late Pleistocene in north-central Chile (31°S-36°S)
    (2024) Gonzalez-Guarda, Erwin; Segovia, Ricardo A.; Valenzuela, Matias; Asevedo, Lidiane; Villavicencio, Natalia; Tornero, Carlos; Ramirez-Pedraza, Ivan; Ortega, Sebastian; Capriles, Jose; Labarca, Rafael; Latorre, Claudio
    Limited pollen and limnogeological evidence show that central Chile (31 degrees S-36 degrees S) had a more temperate climate during the Late Pleistocene. Questions remain, however, regarding the extent of the mediterranean sclerophyllous forest currently found in this region and its postglacial dynamics. The extinct Notiomastodon platensis was the only proboscidean species that inhabited central Chile and ranged across a broad latitudinal range (31 degrees S-42 degrees S) during the Pleistocene. Although this species was a mixed-feeder, we reconstructed past ecosystems when these animals were alive using stable isotope evidence from dental root collagen (delta C-13 and delta N-15) of N. platensis specimens collected from present-day semi-arid and mediterranean ecosystems in central Chile (31 degrees S-36 degrees S). Compared to modern vegetation isotope baselines, we expected the isotopic value of the Estimated Consumed Diet (ECD) (the probable diet of N. platensis) to be similar to the isotopic signal (low values) from vegetation adapted to temperate rainforests. However, elevated delta N-15(ECD) values indicate a paleo-vegetation more similar to a xerophyte scrub influenced by a semi-arid paleoclimate. delta C-13(ECD) values reflect a wooded/forested environment but adapted to more arid conditions. Although high delta N-15 values could be influenced by other non-climatic factors (e.g., grazing effect), our combined evidence suggests that these gomphotheres roamed through ecosystem very similar to those found today in central Chile. Our results show the need for multiproxy reconstructions of past environmental change in Mediterranean regions where the abundance of entomophilous species can lead to biased pollen reconstructions.