Abstract:
For most of the past 150 years the presence of only giant megatheriine ground sloths in the Pleistocene of Brazil has been recognised. However, it has recently been claimed that a dwarf Eremotherium species was present sympatrically with the large-sized giant ground sloth in northeastern and southeastern Brazil during the late Pleistocene and that the concept of a single Panamerican species was improbable. Based on analysis of the ontological sequence of skull suture closure and dental development of remains from a single locality, we demonstrate that the 'dwarf' species is based on the remains of immature individuals, at very early ontogenetic stages, of the large-sized species. Further, we reaffirm that the most parsimonious hypothesis is to consider all large-sized Eremotherium remains as belonging to a single species of Panamerican distribution.
