Unexpected larger distribution of paleogene stem-rollers (AVES, CORACII): new evidence from the Eocene of Patagonia, Argentina.

摘要: Here we present the first record of a stem-Coracii outside Holarctic region, found in early Eocene Patagonia at Laguna del Hunco locality. Ueekenkcoracias tambussiae gen. et sp. nov. consists an incomplete right hind limb that presents following combination characters, characteristic Coracii: relatively short and stout tibiotarsus, poorly developed crista cnemialis cranialis, wide tarsometatarsus, with tuberositas m. tibialis cranialis located medially on shaft, curved ungual phalanges. Although presence rounded conspicuous foramen vasculare distale trochlea metatarsi II strongly deflected resemble Primobucconidae, fossil group only Europe North America, our phylogenetic analysis indicates new taxon is basalmost known Coracii. The unexpected South America this clade had more widespread distribution than previously hypothesized, already extending into Southern Hemisphere by Eocene. represents evidence increasing diversity stem lineages birds material provides novel morphological data for understanding evolutionary origin radiation rollers important estimates divergence time group.