INVESTIGADORES
GALLI claudia ines
artículos
Título:
The Sclidotheriine Proscelidodon (Xenarthra: Mylodontidae) from the Late Miocene of Maimará (Northwestern Argentina).
Autor/es:
PUJOS F., ; CANDELA, A., ; GALLI, C.I.; COIRA, L.B.,; REGUERO, M., ; DE LOS REYES, M.; ABELLO, M.
Revista:
AMEGHINIANA
Editorial:
ASOCIACION PALEONTOLOGICA ARGENTINA
Referencias:
Lugar: Buenos Aires; Año: 2012 vol. 49 p. 668 - 674
ISSN:
0002-7014
Resumen:
Xenarthra constitutes one of the most peculiar clades of
the South American mammalian fauna and includes sloths
(Tardigrada), anteaters (Vermilingua), and armored xenarthrans
(Cingulata). Its phylogenetic affinities among placental
mammals and their origins remain doubtful (Asher and
Helgen, 2010). Xenarthrans first appear in the Itaboraian
age (late Paleocene?early Eocene; Oliveira and Goin, 2011)
represented by the Dasypodidae in the locality of Itaboraí,
Brazil. Sloths are first recorded from the early Oligocene
(Tinguirirican age) of Chile and became abundant during
the late Oligocene (Deseadan age), mainly in Argentina and
Bolivia with representation of Mylodontidae and Megalonychidae
(Pujos et al., 2012).
The mylodontid clade is divided into two subfamilies:
Mylodontinae and Scelidotheriinae following Gaudin
(2004) and St-André et al. (2010). The Scelidotheriinae
includes some of the most spectacular of the giant tardigrades,
with several medium- to large-sized Quaternary
forms. For example, Scelidotherium leptocephalum Owen,
1839, attained the size of a cow; it was a selective browser
(Bargo et al., 2006a), capable of digging and excavated
extensive burrows (Vizcaíno et al., 2001). These ground
sloths were mainly characterized by an extremely specialized,
elongated, and tubular skull, increasing number of lobes on the distal lower molariforms, pentadactyl manus
and pes, flattened femur, and a concave cuboidal facet in
the astragalus.
Proscelidodon Bordas, 1935 appeared during the
Huayquerian in Argentina and survived until the Chapadmalalan.
The Quaternary witnessed the taxonomic diversification
of the Scelidotheriinae, with four species belonging to
the genera Scelidodon Ameghino, 1881, Catonyx Ameghino,
1891, and Scelidotherium Owen, 1840, which ranged across
more than half of southern South America.
Pre-Quaternary Scelidotheriinae are uncommon. The
discovery of a nearly complete maxilla of Proscelidodon from
the Maimará Formation (late Miocene), Jujuy Province (Fig.
1), provides new data on the plesiomorphic condition of
the clade, the biogeographic history of the group during the
Mio?Pliocene, and on the Maimará faunal assemblage.