A Peculiar specimen of Panochthus (Xenarthra, Glyptodontidae) from bolivian altiplano

ZAMORANO M.; ZURITA A. E.

Congreso; 1st Palaeontological Virtual Congress; 2018

Panochthus Burmeister is one of the most diversified and widely distributed glyptodonts in the Pleistocene of South America, reaching the Chaco-Pampean and intertropical regions up to more than 4000 m in high elevation areas. Six species (P. intermedius Lydekker, P. subintermedius Castellanos, P. tuberculatus (Owen), P. frenzelianus Ameghino, P. greslebini Castellanos, and P. jaguaribensis Moreira) are currently recognized. In Bolivia, a new species was recently described (P. hipsilis Zurita, Zamorano, Scillato-Yané, Fidel, Iriondo and Gillette), in addition to an occurrence of P. intermedius, both coming from the center-south region. Here we report a dorsal carapace (UATF-V s/n) from the Pleistocene of the surroundings of Potosí, Bolivia, showing a peculiar combinations of features: a) the total length is similar to P. hipsilis; b) its maximum dorso-ventral diameter is at the level of the anterior half; c) the dorsal profile is different from the remaining species in which this structure is known (P. intermedius, P. frenzelianus, P. subintermedius, P. tuberculatus); d) the ornamentation pattern of the osteoderms shows a central figure surrounded by small polygonal figures throughout the carapace, in contrast to the remaining species, in which central figures are only present in the caudal/cephalic and most lateral regions of the carapace. The specimen here described could belong to P. jaguaribensis in which the carapace is not known; alternatively, it could correspond to a new species or shows that the intraspecifc variation in Panochthus is not sufficiently studied. In any case, further studies and findings are necessary to confirm or refute these hypotheses.