A skeleton of a small bird with a distinctive furcula morphology, from the Rupelian of Poland, adds a new taxon to early Oligocene avifaunas

Abstract

A partial skeleton of a new small avian species is reported from marine sediments of the Rupelian locality Jamna Dolna 2 in southeast Poland. Carpathiavis meniliticus gen. et sp. nov. is characterized by an unusual furcula morphology with stout shafts (scapi clavicularum) and a long, rodshaped furcular apophysis. With regard to furcula shape and the proportions of the wing bones, the new species shows a resemblance to the taxon Eocuculus, which occurs in the late Eocene of North America and the early Oligocene of France. However, there are some distinct differences to Eocuculus, and in overall morphology C. meniliticus is also similar to the late Paleocene/early Eocene taxon Songzia, which is a putative representative of the Ralloidea (rails and allies). Even though a wellfounded phylogenetic assignment of the new species is impeded by the poor preservation of the skeleton, Carpathiavis clearly represents a distinctive new taxon that has not previously been reported from the Rupelian of Europe. In its skeletal morphology, the new taxon differs from all extant avian clades and substantiates previous evidence that in the early Oligocene morphologically distinctive representatives of extinct clades lived alongside essentially moderntype representatives of extant avian groups.