The last glyptodonts (Xenarthra, Glyptodontidae) of the Dry Pampa: an updated review of the Quaternary diversity from La Pampa Province, Argentina

Abstract

This study presents the first updated synthesis of the Quaternary Glyptodontidae diversity from La Pampa Province, Central Argentina. The analyzed materials were recovered from localities situated in the current Dry Pampean Region. This review integrates previously reported specimens as well as new records, and provides a more detailed taxonomic understanding of which glyptodonts inhabited this subregion during the Quaternary. The recognized diversity of glyptodonts for the Late Pleistocene-Early Holocene of the Pampean Region includes Neosclerocalyptus cf. N. paskoensis, Panochthus tuberculatus, Glyptodon reticulatus, and Doedicurus sp. These records represent the last glyptodonts that inhabited the region prior to their extinction, and clarify the paleoenvironmental context in which they lived. Available evidence indicates that the fossil-bearing levels were deposited during intervals of intense aeolian activity and cold-arid conditions, followed by more humid phases toward the Holocene. The presence of Neosclerocalyptus, showing cranial features associated with cold and dry climates, together with large grazing herbivores such as Panochthus and Doedicurus, support the predominance of open grasslands dominated by C4 plants. In contrast, the presence of Glyptodon could suggest a more selective feedinghabit compatible with relatively more closed environments. Overall, the taxonomic diversity recovered reflects fluctuating environmental mosaics in the Pampean Region during the Late Pleistocene–Holocene transition.