A new passerine bird from the early Oligocene of Poland

Abstract

We describe a nearly complete articulated specimen representing a new species and genus, Jamna szybiaki gen. et sp. nov., of an early Oligocene passeriform bird from Poland. In overall osteology, the specimen resembles extant Passeriformes but it differs from that group in several characters including the not bifurcated spina externa (sternum) and the absence of a hooked processus acrocoracoideus (coracoid). Its affinities within Passeriformes cannot be resolved at the moment due to the lack of characters that would support its position within either Oscines or Suboscines. For the first time in Paleogene passerines, wing and tail feathers are visible which provide new information on the external appearance of the bird. Its morphology suggests that it was a frugivorous/ insectivorous bird that lived in shrubs and forests.

The third nearly complete passerine bird from the early Oligocene of Europe

“…Only the proximal-most portion of the beak is visible, with the beginning of the narial openings. Unlike J. szybiaki (Bochenski et al 2011), the dorsal bar of the os nasale is wider than the ventral. The mandible is disarticulated from the cranium.…”

“…A great majority of them are marine fish remains, but representatives of other organisms including plants, invertebrates and vertebrates are also sometimes found. So far, birds are represented by two nearly complete specimens-a hummingbird Eurotrochilus noniewiczi (Bochenski and Bochenski 2008) and a passerine Jamna szybiaki (Bochenski et al 2011). Other, less spectacular specimens include a procellariiform ?Diomedeoides lipsiensis (Elzanowski et al 2012), an articulated passerine leg (Bochenski et al 2012a) and a bird of unknown affinities with a columbid-like foot (Bochenski et al 2010).…”

A complete passerine foot from the late Oligocene of Poland

“…Similarly to other bird fossils from the Oligocene of Poland (Bochenski and Bochenski, 2008;Bochenski et al, 2010Bochenski et al, , 2011, particular elements in ZPALWr.A/4005 are broken longitudinally and preserved as imprints partly lined with remnants of bone. Therefore, often a mixture of an imprint and the inner side of a bone rather than its external surface is visible, which sometimes makes it difficult to recognize the left and right sides or the anterior and posterior views at first glance, especially in the photographs.…”

“…In this respect it differed from the early Oligocene Jamna szybiaki, Resoviaornis jamrozi and ZPALWr. A/4004 (Bochenski et al, 2011(Bochenski et al, , 2013a, in press, respectively) that spent much time on the ground, foraging among trees and shrubs.…”

“…The oldest two fossils of possible passerine affinities were found in Australia and are dated to the early Eocene (Boles, 1995(Boles, , 1997, but unquestionable remains of passeriforms come from the Oligocene of Europe. So far only three species based on relatively complete specimens have been described from the Oligocene: Wieslochia weissi Mayr and Manegold, 2006 from Germany Manegold, 2004, 2006a) and two species from Poland -Jamna szybiaki Bochenski, Tomek, Bujoczek, andWertz, 2011 (Bochenski et al, 2011) and Resoviaornis jamrozi Swidnicka, 2013 (Bochenski et al, 2013a). All three species are dated to the early Oligocene, and their systematic position within Passeriformes remains unresolved because they show a mosaic of characters typical for the Oscines or Suboscines.…”