A particular assemblage of Neogene Xenarthra (Mammalia ) from eastern Puna (Argentina): diversity and biochronology

QUIÑONES, SOFÍA I.; MIÑO-BOILINI, A.; ZURITA, A. E.; CONTRERAS, SILVINA; LUNA, CARLOS; CANDELA, A. M.; CAMACHO, M.; ERCOLI, M.; SOLÍS, N.; BRANDONI, D.

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Lugar: Lawrence; Año: 2019 p. 1 - 18

0022-3360

Abstract. ?Xenarthra constitutes is an endemic South American lineage of mammals, and probably the sister clade of the remaining placental mammals. The oldest records come from the latest Paleocene, although its current relictual diversity is much lower compared with that reached in some lapses intervals of the Cenozoic Era. Recently, there was an evident increasing in the knowledge of the evolutionary history of this clade has been largely increased, even thoughdespite much work is still need. Here we describe a A new Neogene Xenarthra (Pilosa and Cingulata) assemblage from two localities of(Calahoyo and Casira) in the Argentine Eastern Puna (Argentina) (Calahoyo and Casira) is described. The newly recorded taxa (Cingulata Dasypodidae, Eutatini, gen. et sp. nov., Stenotatus sp. nov., Machrochorobates scalabrinii and the Tardigrada Mylodontinae, Mylodontinae cf. Simomylodon Pleurolestodon and Simomylodon cf. uccasamamensis Pleurolestodon cf. acutidens) in addition to those already published from Calahoyo (Cingulata Macrochorobates chapadmalensis, Eosclerocalyptus sp. and the Megatheriidae Pyramiodontherium bergi) suggest a Middle Miocene to Late Miocene age for the bearing outcroppinglevels. In Calahoyo, the presence of the Dasypodidae Stenotatus sp. nov. in addition to some rodents currently under study in the lower outcropping levels, suggests a closer paleofaunistic similitude with the palaoefauna recorded in the locality of Cerdas (southern Bolivia), involving probably the last part of the Miocene climatic optimum. The Xenarthra recorded from in middle and upper levels both of outcropping in Calahoyo and those from Casira, suggest a late Miocene (or earliest Pliocene?) age, showing some resemblance with that those registered in the Late Miocene (?Araucanian?) of northwestern Argentina. A comparative analysis between Calahoyo and Casira highlight the absence of Cingulata in the latter and a more high diversity in the former. This situation probably evidences different paleoenvironmentals conditions.