An assessment of the Cenozoic avifauna of Switzerland, with a description of two fossil owls (Aves, Strigiformes)

Abstract

The fossil skeletal record of birds from the Cenozoic of Switzerland is rather poor, despite the fact that avian tracks have been described from twenty tracksites. We review the Swiss fossil skeletal avifauna with emphasis put on new material discovered in the collection of the Natural History Museum Basel. This material includes two new owls (Strigiformes), one from a Late Eocene fissure filling from the Gosgen canal, and another from the Late Oligocene of Mumliswil. The Eocene owl specimen consists of a partial, distal tarsometatarsus, and is therefore too incompletely preserved to allow for reliable hypotheses concerning its taxonomic affinities. It does, however, display features resembling members of the extinct family Palaeoglaucidae. The Oligocene specimen is tentatively attributed to the genus Oligostrix, and it is the youngest representative of the extinct family Protostrigidae. Based on the first complete tarsometatarsus for this family, we erect a new species, ?Oligostrix bergeri. These two specimens represent the first record of fossil owls from Switzerland.