First record and description of an exceptional unborn specimen of Cingulata Glyptodontidae: Glyptodon Owen (Xenarthra)

Abstract

In this article, we report the first finding and description of an unborn specimen of Cingulata Glyptodontidae. This specimen was found inside a well-preserved dorsal carapace assignable to Glyptodon cf. G. elongatus, partially articulated and located in the pelvic portion. It was exhumed from the Pleistocene sediments of Monte Cercado city, Tarija Valley (Bolivia), and it consists of, mainly, a partial skull, a mandible with some molariforms (m4-m8), the distal half of both scapulae, the diaphysis of both femora and other undetermined remains. From an anatomical viewpoint, the presence in this specimen of some characters, especially in the skull, that are very similar to those present in fully developed individuals (i.e. subtriangular outline of the narial aperture) is remarkable; however, the ascending ramus of the mandible describes an angle close to 90° with respect to the horizontal ramus. The only previous mention of an unborn Glyptodontidae comes also from Tarija Valley, but that material is lost.