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.

Chinchillidae and Dolichotinae rodents (Rodentia: Hystricognathi: Caviomorpha) from the late Pleistocene of Southern Brazil

“…According to Buchmann et al (2009) the presence of a fossiliferous bed, lenses of organic matter-rich sediments interpreted as abandoned meanders (oxbow lakes), a high proportion of fossils broken after burial, and occurrence of fossils at a considerable distance from the present course of the creek, suggest that the fossils were accumulated and reworked in a wide flood plain. (Oliveira, 1992;Oliveira et al, 2005;Marcon, 2008;Oliveira & Pereira, 2009;Scherer et al, 2009;Lopes & Pereira, 2010). Remains of medium-and small-sized mammals are scarcely represented.…”

On the fossil Remains of Panochthus Burmeister, 1866 (Xenarthra, Cingulata, Glyptodontidae) from the Pleistocene of southern Brazil

“…These pulses can justify the concurrent presence of genera from intertropical and pampean regions through the Pleistocene, for example : Panochthus, Pampatherium Gervais and Ameghino, 1880, Holmesina Simpson 1930, Glyptodon Owen, 1839and Notiomastodon Cabrera, 1929 in southern Brazil mainly in the plain coast of Rio Grande do Sul. The interesting thing is the simultaneous presence of purportedly endemic intertropical species and pampaean species belonging to those genera in the same area (see Oliveira and Pereira 2009). of the Programa de Pós-Graduação em Geociências/ Universidade Federal do Rio Grande do Sul; FZBRS and LGP-V FURG for the infrastructure provided; D.da Silva, L.Kerber,V.G.…”

Los Peltephilidae (Mammalia, Xenarthra) de la Formación Collón Curá (Colloncurense, Mioceno médio), Argentina

“…La relación entre los elementos epidérmicos (escamas epidérmicas) y los osteodermos, dentro de los Dasypodidae es variable (Simpson, 1948 más de una escama epidérmica por osteodermo, la fi gura central (= fi gura principal o "main fi gure" sensu Oliveira & Pereira, 2009;Porpino et al, 2010) posee su propia escama y las fi guras laterales poseen escamas compartidas por dos, tres o hasta cuatro osteodermos (Holmes & Simpson, 1931;Scillato-Yané, 1982;Wetzel & Mondolfi , 1979;Wetzel, 1985;Vizcaíno, 1994;Carlini et al, 1997;Vickaryous & Hall, 2006;Carlini et al, 2009). Algunos Euphractinae primitivos (i.e.…”

“…Tradicionalmente la nomenclatura utilizada para describir los osteodermos de los Peltephilidae han sido los mismos empleados para los osteodermos de los Dasypodidae y Glyptodontidae (Ameghino, 1887(Ameghino, , 1889Lahille, 1895;Scillato-Yané, 1982;Vizcaíno et al, 2003;Hill, 2006;Croft et al, 2007;Krmpotic et al, 2009;Oliveira & Pereira, 2009;Fernicola & Porpino, 2012).…”