Antlers Matter! Revisiting the Diversity and the Negative Selection of Extinct South American Cervidae (Cetartiodactyla: Mammalia)

MARIS, G.; AVILLA, L.S.; ROTTI, A.; VEZZOSI, R.I.

Corrientes

Jornada; 32 Jornadas de Paleontología de Verbetrados; 2018

CECOAL-CONICET, UNNE, AMEGHINIANA

The South AmericanCervidae (SAC) possibly originated in Early?Middle Pleistocene, and quicklyreached its highest diversity at Late Pleistocene ? 13 genera, with six extanttaxa. However, there is no consensus about the richness of extinct SAC, mainly becausemost taxa have dubious diagnoses founded on very fragmentary fossils and/orsmall sample. Furthermore, extinct SAC taxonomy is based only on antlersdiagnostic features, the most common element preserved. The antler is animportant morphological complex for SAC taxonomy, but only when ontogeny andindividual variations are considered. The antlers development is characterizedby small/fragile/simple (fewer ramifications) appendages on early stages and,large/robust/complex (including palmation in some taxa) in adults. Among allextinct SAC, only Morenelaphus and Antifer have an abundantrecord of well-preserved antlers, which allowed the recognition of complete ontogeneticseries. Paraceros differs from all extinct SAC by simplest but largeantlers with longer pedicle. Antlers of the extinct Andean Odocoileusare larger than those of extant South American Odocoileus, but similarin size to the North American species. Agalmaceros is junior synonym of Odocoileus,since they only differ in very marked bumps on antlers beams of theformer, a populational variation recognized for SAC. Although most authorsargued that Antifer is senior synonym of Epieuryceros, an additionalramification on the palmation of Epieuryceros supports its validity. TheAndean Odocoileus, Paraceros, Epieuryceros, Morenelaphus and Antifershare large (beam) antlers compared to extant SAC, therefore this featureprobably drove them to be negatively selected at Pleistocene/Holocenetransition.