Glyptotherium cylindricum (Cingulata, Glyptodontidae) from the Late Pleistocene of Guatemala: the most complete record of Glyptodontinae from Central America

Abstract

Glyptodontinae stand out among the lineages of Glyptodontidae in having the greatest latitudinal distribution, including participation in the Great American Biotic Interchange, with significant speciation in new migration areas. The oldest records of Glyptodontinae occur in northern South America with Boreostemma from the middle Miocene–Pliocene. A later radiation incorporated the austral representatives ‘Glyptodontidium tuberifer’, ‘Paraglyptodon’ spp., Glyptodon munizi, Glyptodon reticulatus and Glyptodon jatunkhirkhi in the late Miocene–Late Pleistocene of southern South America, and the septentrional representatives Glyptotherium texanum and Glyptotherium cylindricum in the Pliocene–Late Pleistocene of North America, Central America and northeastern South America. Although knowledge of North and South American forms has increased in recent years, records from Central America are still scarce and fragmentary. Here we describe the most complete Central American glyptodontine fossils documented to date, which were recovered from the latest Pleistocene of Guatemala. The remains comprise: (1) an incomplete skull, the right and left hemimandibles, a fragmentary pelvis, cervical and caudal vertebrae, and articulated and isolated osteoderms; (2) a fragmentary pelvis, left hind limb (incomplete autopodium) and seven caudal vertebrae; (3) most of a dorsal carapace; (4) six incomplete caudal armature rings; and (5) a left hemimandible with complete dental series. Comparative assessment indicates that these remains are referrable to G. cylindricum. The presence of this species in northern Central America and northern South America during the latest Pleistocene spans more than 2200 km, suggesting a continuous distribution across this region, at least during the Last Glacial Maximum and the early Younger Dryas.