''Parapengornis'' is an extinct genus of

enantiornithine The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and cla ...

bird from the

Lower Cretaceous Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eight ...

of what is now China. The

holotype specimen A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

was discovered in the

Jiufotang Formation The Jiufotang Formation (Chinese: 九佛堂组, pinyin: ''jiǔfótáng zǔ'') is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms (see ...

near

Lingyuan Lingyuan () is a city in the west of Liaoning province in Northeast China, bordering Hebei province and Inner Mongolia Inner Mongolia, officially the Inner Mongolia Autonomous Region, is an autonomous region of the People's Republic of China. ...

, western

Liaoning province Liaoning () is a coastal provinces of China, province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and i ...

, and was catalogued as IVPP V18687. The nearly complete, articulated specimen is preserved on a slab and has impressions of pennaceous feathers. Only parts of the sternum, the left hand, and right foot are missing. In 2015, it became the basis of the new genus and species ''Parapengornis eurycaudatus'', named by the Chinese palaeontologists Han Hu, Jingmai K. O’Connor, and Zhonghe Zhou. The generic name consists of the Latin word ''para'' and the name of the related genus ''

Pengornis ''Pengornis'' is the largest known enantiornithine bird from the Early Cretaceous of northeast China. The name derives from "Peng", which refers to a mythological bird from Chinese folklore, and "-ornis", which means bird in Greek. ''Pengornis ...

'', indicating their close relationship. The name ''Pengornis'' is itself derived from "Peng", a mythological bird from Chinese folklore, and ''ornis'', which means bird in Greek. The specific name is derived from the Latin words ''eury'', meaning broad, and ''caudatus'', meaning tail, in reference to the broad and expanded

pygostyle Pygostyle describes a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main compon ...

(the last fused vertebrae of a bird's tail). A nearly complete specimen formerly assigned to ''Pengornis'' was also reassigned to ''Parapengornis'' by these authors. Parapengornis skull

''Parapengornis'' was a large pengornithid, distinguished from its relatives by a combination of features such as the many slender, constricted teeth with pointed and recurved apices, with short cervical (neck) vertebrae at the front, but those further back elongated, a broad pygostyle, and a Y-shaped

furcula The (Latin for "little fork") or wishbone is a forked bone found in most birds and some species of non-avian dinosaurs, and is formed by the fusion of the two pink clavicles. In birds, its primary function is in the strengthening of the thoracic ...

(wishbone). Hu and colleagues found physical similarities between ''Parapengornis'' and

scansorial Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose num ...

(tree-dwelling) birds such as

woodpeckers Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. M ...

, and suggested it could have been specialised for climbing vertically and clinging (which had not been previously suggested for early birds, and would add to the diversity of ecological niches occupied by enantiornithines). They also suggested that the pennaceous feathers dominated by rhacis and the shape of the pygostyle may have had a significance for their function. In 2017, Wang Wei and O’Connor argued against the earlier hypothesis that ''Parapengornis'' was woodpecker-like, and found the pygostyle similar to those of other pengornithids, and that the tail feathers could not have worked as a prop. They instead found the tail feathers similar to those of arboreal birds such as the paradise-flycatchers. In 2017, Nikita V. Zelenkov criticised the idea that ''Parapengornis'' was especially adapted for climbing trees.

References

{{Taxonbar, from1=Q41535857, from2=Q47520535 Bird genera Early Cretaceous birds of Asia Enantiornitheans Fossil taxa described in 2015