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Carrillo-Briceno, J. D.

Publications and source records attributed to Carrillo-Briceno, J. D..

2 recordsLinked to original sources

Diverse megamammals exploited by humans, chronology and palaeoecology at Taima-Taima, Late Pleistocene, South America

The arrival of humans to the Americas at the end of the Pleistocene has been one of the foundations of the hypothesis that hunter-gatherer groups had a direct role in the extinction of megafauna. However, empirical evidence of the exploitation of megafauna by humans and associated chronological context are still scarce, especially in South America. Using evidence of modifications on osteological remains, we provide a reassessment of the megafauna that was exploited at the classic Taima-Taima site (Venezuela), with an updated chronology and paleoenvironmental inferences. Our results show that, at least, five species of extinct megaherbivores were probably exploited at the site, expanding the previous records, restricted to the proboscidean Notiomastodon platensis and the giant armadillo Glyptotherium cf. G. cylindricum. The new data of the other exploited taxa include the terrestrial sloth Glossotherium, the macrauchenid cf. Xenorhinotherium bahiense and a toxodontid; both killing and slaughtering activities were likely practised at the site. Seven new enamel radiocarbon dates show an age of 15.3-17.8 cal kyr BP for the fossiliferous strata, although this is likely to be a minimum age given the materials propensity for modern carbon uptake. The study of phytoliths and starch grains from the dental calculus of N. platensis identified five plant taxa from the phytoliths: arboreal dicotyledons, Poaceae, Marantaceae, Asteraceae and Arecaceae. Ecometrics studies of dental diversity reveal how no other single site on the continent preserves such a diversity of grazing and browsing megaherbivores exploited by humans.

paleontology↗

Fossil Freshwater Fishes from the Pliocene of northern Colombia and the Palaeogeography of northern South America

1Freshwater fishes from northern Colombia are reported from the Sincelejo and Ware formations, of Pliocene age. A total of ten taxa have been identified comprising two orders, five families, and nine genera. Characters from dental morphology, fin spines, and cranial bones are provided as taxonomic tools for the study of fossil fishes. All of the taxa are members of groups currently restricted to drainages east of the Andes, suggesting that physical drainage connection was still present by the Pliocene between the Amazon-Orinoco and trans-Andean drainages such as the Magdalena-Cauca, or that these groups persisted in the trans-Andean region at least until Pliocene times. The genera Hemidoras, Serrasalmus, and Trachely-opterichthys are new records for the fossil fish fauna of South America. The genus Zungaro represents a new record for the trans-Andean region, whereas the genus Platysilurus is for the first time in Colombia. Most of these occurrences also represent the youngest occurrences in the fossil record. Literature records are reidentified as Pygocentrus from the La Venta fauna and the earily Oligocene in Peru. These assemblages suggest that the Sincelejo and Ware formations were deposited in rivers of large size that were part of a large drainage network connected to the Amazon-Orinoco despite being currently located west of the Andes. These findings suggest that the Cordillera Oriental and the Merida Andes were not dividing yet the drainage network in northern South America by the middle to late Miocene.

paleontology↗