Pseudoglyptodon

McKENNA, MALCOLM C., WYSS, ANDRÉ R. & FLYNN, JOHN J., 2006, Paleogene Pseudoglyptodont Xenarthrans from Central Chile and Argentine Patagonia, American Museum Novitates 3536 (1), pp. 1-20 : 4-5

Pseudoglyptodon , unnamed species

REFERRED SPECIMENS: AMNH 29483 ( fig. 1 ), a mandibular fragment bearing one complete cheek tooth and part of a second, discussed and figured by Simpson (1948: 93, fig. 23) as ‘‘Glyptodont, incertae sedis, perhaps Glyptatelus ’’, and also in more general terms by Hoffstetter (1958: 573, fig. 25). A cheek tooth from the Mustersan (or later; see below) of Patagonia referred by Ameghino (1902) to Glyptatelus fractus is here referred to Pseudoglyptodon , pertaining to the same unnamed species as AMNH 29483.

LOCALITY INFORMATION: Cerro Blanco, Chubut Province, Argentine Patagonia. Simpson (1948) provided no precise information about the provenance of AMNH 29483, nor is the specimen mentioned in his unpublished field notes. Nevertheless, the specimen’s label reads, ‘‘Musters Formation, F5 beds, Cerro Blanco, Expedition ’30.’’ The provenance of Ameghino’s specimen is uncertain.

AGE: Mustersan, according to Simpson (1948). The Mustersan, traditionally considered medial Eocene in age, has recently been suggested to be substantially younger, i.e., to postdate 35–36 Ma (Kay et al., 1999).

DIAGNOSIS: Cheek-tooth wall of hard dentine thicker than in P. sallaensis and lobes less angular. Differs from P. chilensis in smaller size (the lower tooth row being,30% shorter anteroposteriorly).

COMMENT: These small Pseudoglyptodon cheek teeth are evidence of little but the presence of the taxon in Mustersan deposits, but this at least confirms other pre-Deseadan records for early phyllophagans in South America (Hoffstetter, 1958: 573).

Figures

Fig. 1. AMNH 29483, mandibular fragment bearing one complete cheek tooth and part of a second, collected by G.G. Simpson from Cerro Blanco, Chubut Province, Argentina. Identified by Simpson (1948: 93) as ‘‘Glyptodont, incertae sedis, perhaps Glyptatelus’’, this specimen is here transferred to a new, but unnamed, species of Pseudoglyptodon. Reproduced from Simpson (1948: 93, fig. 23). Scale, 2X.