Jeholornithidae is a family of

avialan Avialae ("bird wings") is a clade containing the only living dinosaurs, the birds. It is usually defined as all theropod dinosaurs more closely related to birds (Aves) than to deinonychosaurs, though alternative definitions are occasionally used ...

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

s whose taxonomy is controversial, whose remains are found in fossil deposits of what is now

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. The controversy stems from whether most of the taxa in the group are just specimens of ''

Jeholornis ''Jeholornis'' (meaning "Jehol bird") is a genus of avialans that lived between approximately 122 and 120 million years ago during the early Cretaceous Period in China. Fossil ''Jeholornis'' were first discovered in the Jiufotang Formation in Heb ...

'', as well as if the group is monophyletic at all. In the description of '' Kompsornis'' the authors Wang ''et al''. (2020) found moderate support in the monophyly of the group, placing them as basal avialans sister to

Pygostylia Pygostylia is a group of avialans which includes the Confuciusornithidae and all of the more advanced species, the Ornithothoraces. Definition The group Pygostylia was intended to encompass all avialans with a short, stubby tail, as opposed to t ...

. No

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

definitions for these groups were provided by Zhou and Zhang, but a topological definition was provided in 2020 by Wang and colleagues where Jeholornithiformes was defined as "the most inclusive clade containing ''Je. prima'' but excluding the extant birds". The results of a phylogenetic analysis of all valid jeholornithiform species considered by Wang and colleagues is shown below:

References

Prehistoric avialans Prehistoric dinosaur families Early Cretaceous dinosaurs of Asia Taxa named by Zhou Zhonghe {{Theropod-stub