Passerine diversity in the late Oligocene of Germany: earliest evidence for the sympatric coexistence of Suboscines and Oscines

Abstract

A passerine avifauna from the late Oligocene (c. 26–25 mya) of Germany was characterized by a high diversity of conspicuously small birds ranging in size from the smallest known Oscines to moderately small forms. The avifauna comprised both Oscines and Suboscines. Other passerine fragments showed such an unexpected mosaic of characters that it was impossible to assign them with certainty to any subordinate clade within the Passeriformes. The isolated remains of oscine passerines are the earliest evidence of this taxon in the Northern Hemisphere. Coexistence of oscine and suboscine passerines during the late Oligocene is also documented for the first time in the Northern Hemisphere. These finds reduce a major gap in the passerine fossil record and allow new insights into the composition and natural history of ancient avifaunas.

A new passerine bird from the early Oligocene of Poland

“…The distal end is wide; the condylus dorsalis projects dorsally. The exact shape and size of the processus supracondylaris dorsalis cannot be discerned but it is clear that the process is just above the condylus dorsalis, which agrees with the condition in Passeriformes (Manegold 2008) and Zygodactylidae (Mayr 1998(Mayr , 2008Weidig 2010). The processus flexorius is prominent and it projects distinctly distally, which is in agreement with extant Passeriformes, the Oligocene Wieslochia (Mayr and Manegold 2006a) and the extinct Zygodactylidae (Mayr 1998(Mayr , 2008.…”

“…As noticed in previous studies (Manegold 2008;Mayr 2009;Mayr and Manegold 2006a), all passerine remains from the Oligocene represent small and very small taxa, which may indeed reflect their real proportion in the avifauna. Our results confirm the observation by adding another small species to the Oligocene passerines.…”

“…As in most extant Oscines, the ventral surface of the synostosis metacarpalis distalis bears a fossa (Mourer-Chauviré et al 1989). Such a distal depression is also present only in a few Suboscines, which is best explained as convergence (Manegold 2008).…”

“…The remaining passerine remains are from the Oligocene of Europe. They include several dozen isolated bones from various localities of France and Germany (Manegold 2008;Mourer-Chauviré 2006;Mourer-Chauviré et al 1989), an articulated wing from France (Mayr and Manegold 2006b), two so far undescribed articulated legs from Poland (Bocheński 1989(Bocheński , 1993(Bocheński , 1996, one nearly complete specimen (preserved on two slabs in separate collections) and a skull of Wieslochia weissi from Germany Manegold 2004, 2006a), and a so far undescribed specimen from France (Roux 2002). The remains represent both Oscines and Suboscines (Manegold 2008;Mayr 2009;Mourer-Chauviré 2006).…”

A complete passerine foot from the late Oligocene of Poland

“…Another complete specimen of a passerine bird was found in the early Oligocene of Lubéron, France, but it has not been described yet (Mayr, 2009). The remaining Oligocene remains described in the literature include an articulated wing (Mayr and Manegold, 2006b) and a handful of isolated wing bonesthose from the late Oligocene represent both Oscines and Suboscines (Manegold, 2008;Mourer-Chauviré et al, 1989). Leg bones and especially their distal elements are even rarer.…”