New analysis of Vetelia gandhii (Xenarthra, Cingulata) gives a novel hypotheris: was this armadillo a carnivorous tolypeutine?

BARASOAIN, D.; GONZÁLEZ RUIZ, L.R.; TOMASSINI, R.L.; ZURITA, A.E.; CONTRERAS, V.

Congreso; IInd Palaeontological Virtual Congress; 2020

Vetelia is a genus of armored xenarthrans traditionally included within the subfamily Euphractinae (Chlamyphoridae), restricted to the Miocene of Argentina. It includes the species V. puncta (early and middle Miocene, Santacrucian, Friasian s.s., and Colloncuran SALMA), V. perforata (middle and late Miocene; Mayoan, Chasicoan, and Huayquerian), and V. gandhii (late Miocene; Chasicoan/Huayquerian), known mostly by isolated osteoderms. In this contribution, we analyze and describe cranial and postcranial remains assigned to V. gandhii (PVSJ-289; PVSJ-154) from the late Miocene of Loma de Las Tapias Formation (Chasicoan SALMA) of San Juan Province, Argentina. Its morphology suggest higher affinity with the extant representatives of Tolypeutinae, namely the genera Priodontes, Cabassous, and Tolypeutes, rather than those of Euphractinae based on: i) similar shape and ornamentation pattern of both fixed and mobile osteoderms of the dorsal carapace, ii) wide and low osteoderms figures with external rugose surface, and iii) fixed osteoderms becoming subcircular towards the carapace lateral margins. Though molecular analyses and the Oligocene cingulate Kuntinaru support the divergence of the tolypeutines at ~26 Ma, remains of these armadillos are extremely scarce, with a gap of 12 Ma in the fossil record. Additionally, this circumstance could be enhanced by a historic misidentification of Tolypeutinae diagnostic characters. Additionally, we carry out for the first time an anatomical analysis over Vetelia cranio-mandibular features, which are characterized by a dorsoventrally expanded rostrum, very robust horizontal ramus, powerful anterior dentition, massive chisel-shaped molariforms, and absence of anterior dental diastema, suggesting a trend or specialization towards carnivory.