Rising from the ashes: The biggest South American deers (Cetartiodactyla: Cervidae) once roamed Northeast Brazil

Abstract

The tragic fire at the National Museum (Brazil) in September 2018 caused invaluable losses to South American natural and cultural heritage. However, previous visits to the paleontological collection generated photographic and descriptive records of mammalian fossil specimens from the Pleistocene of Brazil. Thus, it was possible to redescribe and revise the taxonomy of Cervidae fossils from two important paleontological sites in the Brazilian Intertropical Region (João Cativo and Lage Grande). These fossils include antlers and lower teeth, and they were described and taxonomically identified by morphological comparisons with all extant and extinct South American deers. A new diversity of Cervidae was recognized, differently from that proposed in the literature, which recognized the presence of Hippocamelus sulcatus, Mazama americana, and Ozotoceros bezoarticus. Instead, the Cervidae fossils from João Cativo and Lage Grande sites belong to the extinct deer Morenelaphus. Although some specimens could not be identified at a specific level (Cervidae indet.), a comparative analysis of the estimated body mass pointed out the most massive deer in South America (including extinct and extant) and recognized Morenelaphus as the second heaviest. The record of these large deers with huge antlers suggests the presence of natural grasslands areas and milder climatic conditions for late Pleistocene in the Brazilian Intertropical Region. Climatic and environmental changes may have driven these large deers to extinction in the Pleistocene/Holocene transition. This study reveals an unprecedented Cervidae diversity for the Brazilian Intertropical Region, emphasizes the relevance of dental features, together with antlers morphology, in taxonomic studies of Cervidae, and also highlights the importance of South American natural heritage in the retrieving of knowledge and new scientific discoveries through collection specimens.