''Mystiornis'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

which existed in what is now western

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

during the early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

period (

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is precede ...

/ Aptian age). It is known from an isolated

metatarsus The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the me ...

found in the Shestakovo-1 locality of southern Western

. It was named by Evgeny N. Kurochkin, Nikita V. Zelenkov, Alexandr O. Averianov and Sergei V. Leshchinskiy in 2011, and the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

is ''Mystiornis cyrili''. While most recent studies place it as an Enantiornithine, specifically an Avisaurid, the authors note that the placement in both groups is tentative and further material will be required to make a firm decision on placement due to the unusual features of the existing material. Based on the strongly shortened metatarsal II and orientation of throchleae, ''Mystiornis'' had diving adaptations similar to that of ''

Gansus ''Gansus'' is a genus of aquatic birds that lived during the Aptian age of the Early Cretaceous (Aptian-Albian) period in what are now Gansu and Liaoning provinces, western China. The rock layers from which their fossils have been recovered are d ...

'' and ''

Neogaeornis ''Neogaeornis'' is a controversial prehistoric genus of diving bird. The single known species, ''Neogaeornis wetzeli'', was described from fossils found in the Campanian to Maastrichtian Quiriquina Formation of Chile. It lived about 70-67 million ...

''. It was the size of a thrush.

References

Early Cretaceous birds of Asia Avisaurids Fossil taxa described in 2011 Extinct animals of Russia {{paleo-bird-stub