Jeholornithidae is a family of

avialan Avialae ("bird wings") is a clade containing the only living dinosaurs, the birds, and their closest relatives. It is usually defined as all theropod dinosaurs more closely related to birds (Aves) than to deinonychosaurs, though alternative defi ...

theropod Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...

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. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. 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 avialan dinosaurs 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 Formati ...

'', 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 and 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 t ...

. No

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

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

Dinosaur families Aptian dinosaurs Dinosaurs of China {{Paleo-bird-stub