A phylogenetic reassessment of the fossil record of tinamous (Palaeognathae, Tinamidae)

BERTELLI, S.; CHIAPPE, L.M.

Quillan

Congreso; Sixth International Meeting of the Society of Avain Paleontology and Evolution; 2004

Centre National de la Recherche Scientifique y Association Dinosauria

The scant fossil record of tinamous is mostly limited to isolated bones. Although ghost lineage inference (based on the Paleocene record of its sister-group, the ratites) indicates a much deeper origin, the known fossil record of tinamous is limited to the Early Miocene-Present interval. The earliest fossils are from the Pinturas and Santa Cruz formations of southern Patagonia (Argentina). Fossil tinamous are also known from the Lower-Middle Monte Hermoso Formation and the Upper Pleistocene (Buenos Aires and Chapadmalal formations) of this country. No Tertiary fossils have been recorded outside Argentina ?only Pleistocene remains are known from Peru and Brazil. While Tertiary records appear to belong to extinct taxa (e.g., unnamed taxa from the Early Miocene and the Lower-Middle Pliocene Eudromia olsoni and Nothura parvula), most Quaternary tinamous have been assigned to living species (the sole published exception is Nothura paludosa from Argentina). In order to assess the phylogenetic placement of these fossils, we have scored their morphological information within a data matrix of 107 osteological characters and 40 living species of tinamous. The distribution of these fossils within the resultant cladograms is discussed in light of their significance for the understanding of the evolution of the two main ecological subdivisions of these birds?the forest-dwelling taxa (traditionally classified in the paraphyletic taxon "Tinaminae") and the open-area tinamous (the monophyletic Nothurinae).