Zhyraornis is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of prehistoric bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 from the late Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 period (middle Turonian

Turonian

The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...

, 92 mya). Its fossils have been found in Bissekty Formation

Bissekty Formation

The Bissekty Formation is situated in the Kyzyl Kum desert of Uzbekistan, and dates from the late Cretaceous Period. Laid down in the early the Turonian to Coniacian stages, it is dated to about 90-85 ma .The Bissekty Formation is characterised by a mix of marine, brackish, freshwater, and...

 deposits near Dzharakuduk in the Kyzyl Kum

Kyzyl Kum

The Kyzyl Kum , also called Qyzylqum, is the 11th largest desert in the world. Its name means Red Sand in Turkic languages. It is located in Central Asia in the doab between the rivers Amu Darya and Syr Darya, and is divided between Kazakhstan, Uzbekistan and Turkmenistan...

, Uzbekistan

Uzbekistan

Uzbekistan , officially the Republic of Uzbekistan is a doubly landlocked country in Central Asia and one of the six independent Turkic states. It shares borders with Kazakhstan to the west and to the north, Kyrgyzstan and Tajikistan to the east, and Afghanistan and Turkmenistan to the south....

. Two species have been assigned to this genus: Zhyraornis kashkarovi and Zhyraornis logunovi. Both are known only from partial pelvic bones (synsacra).

Classification

The relationships of this bird are unresolved. Paleontologist Lev Nesov originally classified in a distinct family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 (Zhyraornithidae) and later suborder (Zhyraornithi) within the order Ichthyornithiformes. Kurochkin (1996) considered it to belong to the Enantiornithes

Enantiornithes

Enantiornithes is an extinct group of primitive birds. They were the most abundant and diverse avialans of the Mesozoic. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over 50 species of Enantiornithines have been named, but some...

, specifically the family Alexornithidae

Alexornithidae

Alexornithidae is an extinct family of enantiornithine birds.*Order Alexornithiformes** Family Alexornithidae***Alexornis ***Kizylkumavis ***Sazavis...

. In 2006, Kurochkin re-classified it as a primitive member of the lineage leading to modern birds, the Ornithuromorpha.