Neosclerocalyptus spp. (Cingulata, Glyptodontidae, Hoplophorini): cranial morphology and palaeoenvironments, along the changing Quaternary

ZURITA, A. E.; SCARANO, A. C.; CARLINI, A. A.; SCILLATO-YANÉ, G. J.; SOIBELZON E.

JOURNAL OF NATURAL HISTORY

TAYLOR & FRANCIS LTD

Año: 2011 vol. 45 p. 893 - 914

0022-2933

We propose that the particular high latitudinal distribution of Neosclerocalyptus(Glyptodontidae) and the cyclic nature of the Pleistocene glacial–interglacial eventswere factors that probably stimulated morphological evolution of its fronto-nasalsinuses, a feature unique among glyptodonts. The distributions of the species, andthe majority of its records, are associated with sediments related to arid and semiaridenvironments. Four species are recognized during the last million years insouthern South America. The first record of Neosclerocalyptus (N. pseudornatus)coincides with the “Great Patagonian Glaciation” and shows the lowest gradeof pneumatization on its skull. Neosclerocalyptus paskoensis (the most derivedspecies), limited to Oxygen Isotopic Stage 2, shows the greatest development offronto-nasal pneumatization. The restricted geographic range of Neosclerocalyptus,the possible absence of geographic barriers during the Pleistocene, and the absenceof cases of sympatry, allow us to speculate the existence of a single continuouslineage of successive species, showing an anagenetic process.