Arctotherium wingei

[surroundx]

Soibelzon, Leopoldo H. and Rincón, Ascanio D. (2007). The fossil record of the short-faced bears (Ursidae, Tremarctinae) from Venezuela. Systematic, biogeographic, and paleoecological implications. N. Jb. Geol. Palaont. Abh. 244(3):287-298.

[Sebbe]

According to this paper it is not certain that this species survived into the Holocene. The last known records of A. wingei from Sistema Sac Actun (Yucatán), Mexico dates back to 12,850 while the record from Venezuela dates back to somewhere between 9,030 and 16,375 years ago.

Yucatán carnivorans shed light on the Great American Biotic Interchange.

The Great American Biotic Interchange is considered to be a punctuated process, primarily occurring during four major pulses that began approximately 2.5 Ma. Central America and southeastern Mexico have a poor fossil record of this dynamic faunal history due to tropical climates. Exploration of submerged caves in the Yucatán, particularly the natural trap Hoyo Negro, is exposing a rich and remarkably well-preserved late Pleistocene fauna. Radiometric dates on megafauna range from approximately 38 400–12 850 cal BP, and extinct species include the ursid Arctotherium wingei and canid Protocyon troglodytes. Both genera were previously thought to be indigenous to and confined to South America and appear to represent an instance of large placental mammals, descended from North American progenitors, migrating back north across the Panama Isthmus. This discovery expands the distribution of these carnivorans greater than 2000 km outside South America. Their presence along with a diverse sloth assemblage suggests a more complex history of these organisms in Middle America. We suggest that landscape and ecological changes caused by latest Pleistocene glaciation supported an interchange pulse that included A. wingei, P. troglodytes and Homo sapiens.

www.ncbi.nlm.nih.gov/pmc/articles/PMC6548739/

[Sebbe]

Isotopic palaeoecology (δ13C) of three faunivores from Late Pleistocene of the Brazilian intertropical region.

The palaeoecology of megamammals has been commonly accessed by stable isotope. Particularly in the Americas, this approach has been focusing efforts on the study of intertropical species, especially from a key paleozoogeographical region in the Late Quaternary of South America: the Brazilian Intertropical Region (BIR). Here we present an isotopic study (δ13C) conducted on bioapatite samples of Smilodon populator, Protocyon troglodytes and Arctotherium wingei from the BIR. We discuss their potential prey preferences, niche width and overlap, and paleoenvironmental reconstitutions. Our results suggest a generalist carnivorous diet for P. troglodytes (δ13C = – 5.0 ‰; BA = 0.83), a specialist C3 herbivorous diet and opportunistic scavenger behaviour for A. wingei (δ13C = – 11.0 ± 2.1 ‰; BA = 0.00), and a specialist carnivorous diet for S. populator (δ13C = – 8.5 ± 1.6 ‰; BA = 0.06). Within the Late Pleistocene of the BIR, P. troglodytes possibly inhabited open savanna-like environments, while S. populator and A. wingei occupied arboreal savanna forests. An atypical preference for small and medium-size prey for the predator S. populator, and a mainly herbivorous diet with a slight amount of meat for the bear A. wingei is also discussed.

www.tandfonline.com/doi/full/10.1080/08912963.2021.1933468