Myrmecophaga tridactyla (Linnaeus, 1758) subfossils from Abismo Anhumas, Bonito/MS, Brazil: Morphology, isotopic habitat (δ13C, δ18O), radiocarbon dating, biogeography and human impact on the species conservation in Brazil

Abstract

Myrmecophaga tridactyla Linnaeus, 1758 is the largest extant anteater, being distributed in most biomes from southern Central America and northern South America. Herein, we analyzed cranial and postcranial elements of three partial skeletons of M. tridactyla found submerged in Abismo Anhumas cave (Bonito, Mato Grosso do Sul, Brazil). The bones collected were the skull (LEG 2598), left humerus (LEG 2601), ungueal phalanx (LEG 2602), and lumbar vertebrae (LEG 2599; LEG 2600). Radiocarbon dating and isotope analyses indicate that these animals lived between 360 and 560 cal a BP in an arboreal to open savanna habitat associated with the Cerrado, a Seasonal Dry Forest. Radiocarbon-dated oxygen isotopes are possibly in agreement with dated oxygen isotopes found in stalagmites, suggesting a wet period between 442–364 cal a BP in the region. Finally, we created paleo-species distribution models, which allowed the generation of a consensus map showing a historically stable area between 21 and 6 ka for this species. Currently, more than 50% of this area has been destroyed by human activity.