Punatherium catamarcensis, Ciancio & Herrera & Aramayo & Payrola & Babot, 2016

Ciancio, Martín R., Herrera, Claudia, Aramayo, Alejandro, Payrola, Patricio & Babot, Judith, 2016, Diversity of cingulate xenarthrans in the middle-late Eocene of Northwestern Argentina, Acta Palaeontologica Polonica 61 (3), pp. 575-590 : 584-586

Punatherium catamarcensis sp. nov.

Fig. 6P, Q .

Etymology: In reference to the Catamarca Province ( Argentina), where the type locality is located.

Type material: Holotype: MLP 93 -VI-1-18, fixed osteoderm . Paratype: MLP 86 -V-6-24, semimovable osteoderm .

Type locality: Antofagasta de la Sierra, Catamarca Province, Argentina . Type horizon: Middle member of Geste Formation (sensu Alonso 1992); middle–late Eocene.

Diagnosis.—Dorsal shield osteoderms with rugose surface, with circular foramina in the sulci between figures, and in the lateral and posterior margins. Osteoderms ornamentation with a lageniform principal figure with keeled boss that is rounded and high, and anterior and anterolateral peripheral figures. Fixed osteoderms with large principal lageniform figure that occupies the entire posterior half of the osteoderm and becomes narrower anteriorly, surrounded by three anterior and a pair of anterolateral figures. Semimovable osteoderms also with large lageniform principal figure occupying the posterior two thirds of the dorsal surface, the sulcus surrounding the anterior portion of the principal figure with a row of large circular perforations. At both sides of the narrower part of the main figure there are two pairs of anterolateral figures.

Description.—Medium size armadillo, like the extant Chaetophractus villosus , according to the size of the osteoderms. Fixed osteoderms, probably from the pelvic buckler, with the principal figure anteriorly circumscribed by three conspicuous foramina. In addition, there are similar foramina located at the lateral and posterior margins, arranged in one pair at the left border, one single foramen at the right margin, and one pair in the posterior border. There are four peripheral figures on the anterior portion of the main figure. Anterior and lateral contact margins between osteoderms are covered by numerous, low and blunt protuberances. The external surface of the semimovable osteoderm shows a lageniform principal figure, also bordered by a series of large perforations in number of six. As in the case of the fixed osteoderm, there are large perforations in the posterior half of the lateral borders of the osteoderms (two on the left and three on the right). On the posterior border there is not any foramen. Proximally, this osteoderm shows two pairs of peripheral figures at both sides of the narrowest portion of the lageniform figure. The anterior margin of the osteoderm is broken, but it preserves a portion of the cranial overlapping region; the transition zone between the overlapping and main region is smooth and poorly developed.

Measurements.—Fixed osteoderm: 13 mm long, 7 mm width, and 3.5 mm thick. Semimovable osteoderm: ca. 16 mm long (the anterior portion is broken, total length could be 20 mm or a bit more), 8 mm width, and 4 mm thick.

Remarks.—This new taxon exhibits some particularities, which prevent its correct suprageneric assignation. The lateral contact surfaces (covered by numerous, low, and blunt protuberances), the presence of well-defined figures, and the thickness of the osteoderms are typical of euphractins. The presence of a lageniform main figure is typical of astegotheriins, but it is also present in primitive euphractins e.g., Archaeutaetus, see Ciancio and Carlini 2008). On the other hand, the presence of foramina around a principal figure (with a well-developed central keel) and the roughness of the external surface resembles Yuruatherium , a peculiar cingulate from the Paleogene of Peru.

Stratigraphic and geographic range.— Type locality and horizon only.

Figures

Fig. 6. Osteoderms of Dasypodidae incertae sedis from the middle member of the Geste Formation, middle–late Eocene, Antofagasta de la Sierra, Catamarca Province, Argentina. A–O. Pucatherium parvum MLP 93-VI-1-17 (A–F), MLP 88-V-10-19 (G–O). P, Q. Punatherium catamarquensis gen. et sp. nov., holotype, fixed osteoderm, MLP 93-VI-1-18 (P) and paratype, semimovable osteoderm, MLP 86-V-6-24 (Q). Photographs (A1−Q1), line drawings (A2−Q2).