Exceptionally preserved osteoderms on the foot of Eutatus seguini (Mammalia, Cingulata)

Abstract

The osteoderms are the building blocks that construct the shields of cingulates. They have been found in the fossil record since the Paleocene and often their surface sculptures permit identification at the species level, although variations are observed among the shields. In this study, we describe the exceptional preservation of a delicate shield on the foot of Eutatus seguini Gervais 1867 (Late Pleistocene). The osteoderms in this region are characterized by their thinness, roughness, and lack of a well-defined ornamental pattern. They feature a rounded anterior border, fine foramina on their exposed surface, and thin hairy foramina on the anterolateral border. This specimen demonstrates that E. seguini also had a foot shield like extant armadillos, although its phylogenetic position within the cingulates is still unresolved.