Title: Intertropical cingulates (Mammalia, Xenarthra) from the Quaternary of Southern Brazil: Systematics and paleobiogeographical aspects
Abstract: Intertropical Pleistocene taxa of dasypodids and pampatheriids are reported for the Lagoon-Barrier III System (Arroio Chuí locality) and for the Touro Passo Formation (Ponte Velha I locality), both from Rio Grande do Sul State, southern Brazil.The record of pampatheriids includes new specimens that confirm the presence of Pampatherium humboldti in the Arroio Chuí assemblage.Material previously assigned to Holmesina majus is identified as H. paulacoutoi.The record of dasypodids includes a large-sized specimen of the genus Dasypus, represented by an isolated pelvic buckler osteoderm, closely related to Dasypus (Hyperoambon) kappleri, and of Propraopus sulcatus, represented by isolated moveable and fixed osteoderms.This southernmost Brazilian record of P. sulcatus extends their distribution by about 2200 km from Lagoa Santa (Minas Gerais State, Brazil).The first record of P. sulcatus also includes specimens previously referred to as Propraopus cf.grandis from the Touro Passo Formation.Propraopus sulcatus differs from P. punctatus and P. grandis in having: osteoderms with wrinkled external surface, with wide and relatively deep sulci; principal figure plane, ranging from subcircular to hexagonal in fixed osteoderms; and moveable osteoderms with principal sulci forming a lageniform figure, and with four to five larger foramina distributed on the posterior half of these sulci.The late Pleistocene mammals of the coastal province and western Rio Grande do Sul were previously considered closely related to those of the Pampean region of Argentina.However, the presence of intertropical mammals in southern Brazil (Arroio Chuí locality and Touro Passo Formation) mixed with Pampean representatives, corroborates the proposal of a close paleobiogeographic relation with assemblages of northern Uruguay and Argentine Mesopotamia.