A systematic reassessment and paleogeographic review of fossil Xenarthra from Peru

FRANÇOIS, PUJOS; RODOLFO, SALAS

BULLETIN DE L'INSTITUT FRANCAIS D'ETUDES ANDINES

Institut Français d'Etudes Andines

Lugar: Lima; Año: 2004 vol. 33 p. 331 - 377

0303-7495

A revision of Peruvian Xenarthra and the discovery of new specimens have increased ourknowledge of the Order in this country. About thirty sites from three geographic regions,Amazonian Forest, the Andes, and the coast have yielded Xenarthra in Peru. The only well known Pre-Pleistocene Xenarthra is Thalassocnus from the Mio-Pliocene of the Pisco Formation. Pleistocene Phyllophaga (Megatheriidae, Nothrotheriidae, Mylodontidae, and Megalonychidae) and Cingulata (Pampatheriidae and Glyptodontidae) are rare in the Amazonian forest region, abundant in the coastal region and are particularly frequent in the Andes (between 2 500 and 4 500 meters). Cingulata are not as diverse and are represented only byH olmesina cf. paulacoutoi along the coast and Glyptodon clavipes in the Andes. The mylodontid Glossotherium sp. is recognized in the entire Peruvian coast and the scelidothere Scelidodon chiliensis is abundant in both the Andes and northern coast region. Pleistocene nothrotheres are found only in the Amazonian forest region (Nothropus priscus in Río Acre). Megatheriidae are well diversified and have an extended geographic range. The tropical genus Eremotherium (E. laurillardi) is present on the northern coast and is possibly represented in Amazonia by a gigantic form. The temperate genus Megatherium is represented in Peru by a small-sized, quadrupedal, and browser of the Andean linage of the subgenus M. (Pseudomegatherium), which includes M. (P.) tarijense, M. (P.) elenense, M. (P.) urbinai, and new species from the northern Andes. Large species of sloths such as Megatherium (Megatherium) americanum, Lestodon sp., and Scelidotherium leptocephalum that are typical of the Argentinian Pampas are absent in Peru. A peculiar new megalonychid was discovered in the north coast region (Cupisnique desert) and in the Andes near Lake Titicaca at Casa del Diablo cave. 14C dating indicates that most of fossil mammals in Peruare Lujanian in age. Along the coast and probably in Amazonia, Xenarthra are found in open localities, in contrast to the Andean region in which most specimens are preserved in caves. InPeru, and all over South America, large Xenarthra did not survive beyond the beginning of theHolocene.