Palaeotis: A Flightless Bird From Eocene Paleogene Europe may NOT be a Ratite

The middle Eocene European “ratite” Palaeotis (Aves, Palaeognathae) restudied once more

Author:

Mayr

Abstract:

Palaeotis weigelti is a flightless, “ratite”-like palaeognathous bird, which occurs in the Middle Eocene of the German fossil sites Messel and the Geisel Valley. The species is known from several specimens, most of which are, however, very fragmentary or poorly preserved. Its phylogenetic affinities are controversial, with earlier authors especially considering close affinities to Struthionidae and Rheidae, and some skeletal features were only briefly described. Moreover, recent molecular analyses congruently indicate that a “ratite” morphology evolved multiple times within palaeognathous birds. The skeletal morphology and phylogenetic affinities of Palaeotis are therefore reanalyzed, and the taxon is subjected to a phylogenetic analysis based on one of the most comprehensive published data sets for palaeognathous birds. In addition to the primary analysis, further analyses were run that were constrained to a backbone topology reflecting the results of sequence-based studies. In none of these analyses was a well-supported placement of Palaeotis obtained, and it is concluded that current data do not convincingly resolve the affinities of this taxon. Palatal morphology of Palaeotis most closely resembles that of lithornithids, another group of palaeognathous birds from the Eocene of the Northern Hemisphere, and there remains a possibility that the “ratite” features of Palaeotis evolved independently from those of the extant taxa.