The first fossil parrot (Aves, Psittaciformes) from Siberia and its implications for the historical biogeography of Psittaciformes

Abstract

Modern parrots (crown Psittaciformes) are a species-rich group of mostly tropical and subtropical birds with a very limited fossil record. A partial tarsometatarsus from the late Early Miocene of Siberia (Baikal Lake) is the first pre-Quaternary find of crown Psittaciformes in Asia (and Siberia in particular) and is also the northern-most find of this bird order worldwide. This find documents a broad geographical distribution of parrots during the warmest phase of the Miocene (the so-called 'Miocene Climatic Optimum'), which has implications for the historical biogeography of Psittaciformes. The presence of parrots on both sides of the Pacific Ocean at the end of the Early Miocene implies a (most probably eastwards) trans-Beringian dispersal which likely took place about 16-18 Ma. The broad Eurasian distribution of parrots in the past further supports a hypothesis that ancestors of modern genera Coracopsis and Agapornis could reach Africa from Eurasia.

The Miocene: The Future of the Past

“…Early to middle Miocene European bird faunas comprised tropical to subtropical parrots, anhingas (snake birds), and flamingos, that disappeared during the late middle Miocene (Dalsätt et al, 2006;Mayr & Göhlich, 2004). Miocene parrots, anhingas, and flamingos are also known from Asia, Africa, the Americas, New Zealand, and Australia (Baird & Vickers-Rich, 1998;Olson, 1985;Worthy et al, 2010Worthy et al, , 2011Zelenkov, 2016). In Patagonia and other open landscapes of South America, cursorial ratites (rhea relatives) were widespread and other cursorial, giant carnivorous birds (the "terror birds," Figure 1) occupied one of the large land-predator niches (Agnolin, 2017;Degrange et al, 2019).…”

A Macaw (Ara sp.) in a Preceramic Site from the Sabana de Bogotá, Colombia, Dated to the Ninth Millennium cal BP

“…The excellent preservation of the Nemocón IV remains, in particular the left tarsometatarsus (Figure 5c), permits its certain taxonomic identification within the order Psittaciformes. Indeed, the presence of the trochlea accessoria metatarsi IV places it within the zygodactyl birds, and the trochlea metatarsi III , which is wider mediolaterally than dorsoventrally, confirms that it belongs to the Psittaciformes (Zelenkov 2016).…”

“…The identification of diagnostic characters for the Nemocón IV macaw (Hargrave 1970; Mayr 2002; Mayr and Göhlich 2004; Zelenkov 2016) was carried out using skeletally mature reference specimens from the bird osteological collections of the Paris National Museum of Natural History (reference numbers starting with LAC) and the bird collection of the Institute of Natural Sciences, National University of Colombia (reference numbers starting with ICN; Supplemental Table 2). For descriptive purposes, we used established anatomical nomenclature (Baumel and Witmer 1993; Gilbert et al 1981; Livezey and Zusi 2006).…”

“…All Psittaciformes are zygodactyl, and like Piciformes and Cuculiformes, they have two pedal digits (II and III) facing forward and two (I and IV) facing backward (Kaiser 2007; Mayr 2002). One of the most distinctive characteristics for distinguishing between zygodactyl birds is the metatarsi IV : it exhibits an accessory trochlea for one of the retroverted digits, and the dorsal opening of the foramen vasculare distale is laterally joined by a bony bridge to the trochlea accessoria of metatarsi IV (Zelenkov 2016). The following characteristics differentiate the Psittaciformes from other modern zygodactyls, such as the Cuculiformes and Piciformes: a broader trochlea metatarsi II with a strong medial inclination (Mayr 2002:723; Zelenkov 2016:2) a trochlea metatarsi III that is wider mediolaterally than dorsoplantarly (Mayr 2002:723, 725) the presence of a furrow for the tendon of the musculus flexor perforates on digiti IV , which separates trochlea metatarsi IV and its accessory trochlea (Mayr 2002:723) the presence of a furrow between the dorsal side of the trochlea metatarsi IV and the incisura intertrochlearis lateralis (Mayr 2002:723, 725) …”

The middle Miocene duck Chenoanas (Aves, Anatidae): new species, phylogeny and geographical range

“…The discovery of Chenoanas in both western Europe and central Asia adds to the emerging picture that the avifaunas from the climatically warm intervals of the Miocene (early to middle Miocene) in western Europe and north/central Asia shared many taxa. In addition to the species mentioned above, a primitive grebe and parrot, recorded recently from the late early Miocene of Siberia (Zelenkov , ), have relatives in western and central Europe. These data allow us to propose that an avian‐based biogeographical realm similar to the modern Palearctic region might already have been present across this territory in the late early and middle Miocene.…”