Articulated avian remains from the early Oligocene of Poland adds to our understanding of Passerine evolution

Zbigniew M. Bochenski, Teresa Tomek, Krzysztof Wertz, Johannes Happ, Małgorzata Bujoczek, and Ewa Swidnicka

Plain Language Abstract

The Passeriformes, also known as passerine or perching birds, is the largest and most diverse order of birds: more than half of the 10,000 modern species are perching birds. Their fossil remains from the Neogene are very abundant, but their Paleogene record is extremely scarce. Fossil remains of possible passerine birds dated to the Eocene were first described about 30 years ago in Australia. Since then, three nearly complete specimens of unresolved affinities within Passeriformes, were described from the early Oligocene deposits in Europe: Wieslochia weissi from Germany, Jamna szybiaki and Resoviaornis jamrozi – both from Poland. An early Oligocene passerine of Lubéron, France, has not been described yet. Other, less well-preserved Oligocene passerines, include an articulated wing, several dozen isolated wing bones, articulated (fragments of) legs, and two fragments of the tarsometatarsus. In total, less than 50 specimens of passerines are known from the Paleogene; most of them are isolated bones and rather poorly preserved imprints on slabs. This paper describes a new species and genus of a passerine bird the size of the extant Great Tit Parus major, imprinted on a slab and a counter slab of the siliceous clayey shales of the Outer Carpathians in southeastern Poland, and dated to the Rupelian, early Oligocene (ca. 31 m.y.a.). Since the bones are articulated and come from the same bird, the specimen provides a unique opportunity to learn its set of characters, and therefore adds to our understanding of the ancestral osteology of passeriforms, which is characterized by a mosaic of characters typical for extant Oscines (songbirds) and Suboscines (the Tyranni). The bird shows a unique manus, with a relatively short carpometacarpus and cleaver-shaped proximal wing phalanx. Besides bones also fragmentary feathers are imprinted on both slabs.

Resumen en Español

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Traducción: Enrique Peñalver (Sociedad Española de Paleontología) or Diana Elizabeth Fernández

Résumé en Français

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Translator: Antoine Souron

Deutsche Zusammenfassung

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Translator: Eva Gebauer

Arabic

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Translator: Ashraf M.T. Elewa

Polski

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Translator:  Dariusz Nowakowski