A new species of Neosclerocalyptus Paula Couto, 1957 (Xenarthra, Glyptodontidae, Hoplophorinae) from the middle Pleistocene of the Pampean region, Argentina

A new species of the genus Neosclerocalyptus Paula Couto, 1957 (= Sclerocalyptus Ameghino, 1891), N. gouldi n. sp. (Cingulata, Glyptodontidae, Hoplophorini) is described. This new taxon, comes from the Bonaerian Stage (middle Pleistocene; c. 0.4-0.13 Ma) of San Andrés de Giles, Buenos Aires province, Argentina. The type consists mainly of an associated skull, mandible and cephalic shield in an excellent state of preservation. Morphological characters that distinguish the species include: a) lesser pneumatization and lateral expansion of fronto-nasal sinuses compared to N. paskoensis; b) descending processes of maxillaries and zygomatic arches very robust and with marked ridges; c) lower third of descending processes markedly inclined toward the sagittal plane; d) inclination of the parieto-occipital skull region intermediate between those of Ensenadan and Lujanian forms; e) infraorbital foramina larger than in N. paskoensis, similar in size to those of N. ornatus; and f) occipital area less expanded laterally than in N. paskoensis. This new taxon completes the chronological distribution of genus Neosclerocalyptus which, until now, included two well-characterized species for the Ensenadan (early Pleistocene: N. pseudornatus and N. ornatus) and one Lujanian (late Pleistocene-early Holocene: N. paskoensis). The Bonaerian species, N. migoyanus, recognized by Ameghino, should be considered as a nomen dubium, due to the lack of diagnostic characters.