Caudipteryx is a genus of small oviraptorosaur dinosaurs that lived in Asia during the Early Cretaceous, around 124.6 million years ago. They were feathered and extremely birdlike in their overall appearance, to the point that some paleontologists suggested it was a bird. Two species have been described: C. zoui, in 1998, and C. dongi, in 2000.
Confuciusornis is a genus of basal crow-sized avialan from the Early Cretaceous Period of the Yixian and Jiufotang Formations of China, dating from 125 to 120 million years ago. Like modern birds, Confuciusornis had a toothless beak, but closer and later relatives of modern birds such as Hesperornis and Ichthyornis were toothed, indicating that the loss of teeth occurred convergently in Confuciusornis and living birds. It was thought to be the oldest known bird to have a beak, though this title now belongs to an earlier relative Eoconfuciusornis. It was named after the Chinese moral philosopher Confucius. Confuciusornis is one of the most abundant vertebrates found in the Yixian Formation, and several hundred complete specimens have been found.
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans, the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over eighty species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs.
Cathayornis is a genus of enantiornithean birds from the Jiufotang Formation of Liaoning, People's Republic of China. It is known definitively from only one species, Cathayornis yandica, one of the first Enantiornithes found in China. Several additional species were once incorrectly classified as Cathayornis, and have since been reclassified or regarded as nomina dubia.
Cuspirostrisornis is a genus of enantiornithean bird. Only one species is known, Cuspirostrisornis houi, though some researchers believe this to be a synonym of the similar species Cathayornis yandica. It is known from one fossil found in the Jiufotang Formation in Liaoning province, People's Republic of China. The Jiufotang Formation is dated to the Early Cretaceous period, Aptian age, 120.3 +/-0.7 million years ago.
Pygostylia is a group of avialans which includes the Confuciusornithidae and all of the more advanced species, the Ornithothoraces.
The Jiufotang Formation is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms. It is a member of the Jehol group. The exact age of the Jiufotang has been debated for years, with estimates ranging from the Late Jurassic to the Early Cretaceous. New uranium-lead dates reveal the formation is deposited in the Aptian stage of the Early Cretaceous. Fossils of Microraptor and Jeholornis are from the Jiufotang.
Protopteryx is an extinct bird and possibly the basalmost enantiornithean, from the Cretaceous period. The type species is P. fengningensis. It was first discovered in the Sichakou Member of the Yixian Formation or Huajiying Formation of Hebei Province, northern China, dating from 131 Ma ago. Protopteryx has been found in the Daibeigou formation, as well. The name Protopteryx means "primitive feather": "proto-" meaning "the first of" and "-pteryx" meaning "feather" or "wing." The name comes from the fact that Protopteryx feathers are more primitive than those of modern birds, such as the two elongated tail feathers that lack barbs and rami.
Shanweiniao is a genus of long-snouted enantiornithean birds from Early Cretaceous China. One species is known, Shanweiniao cooperorum. There is one known fossil, a slab and counterslab. The fossil is in the collection of the Dalian Natural History Museum, and has accession number DNHM D1878/1 and DNHM1878/2. It was collected from the Lower Cretaceous Dawangzhengzi Beds, middle Yixian Formation, from Lingyuan in the Liaoning Province, China.
Longipterygidae is a family of early enantiornithean avialans from the Early Cretaceous epoch of China. All known specimens come from the Jiufotang Formation and Yixian Formation, dating to the early Aptian age, 125-120 million years ago.
Dinosaur coloration is generally one of the unknowns in the field of paleontology, as skin pigmentation is nearly always lost during the fossilization process. However, recent studies of feathered dinosaurs and skin impressions have shown the colour of some species can be inferred through the use of melanosomes, the colour-determining pigments within the feathers.
Parabohaiornis is an extinct genus of bohaiornithid enantiornithean dinosaur known from the Early Cretaceous of Liaoning Province, northeastern China. It contains a single species, Parabohaiornis martini.
Bohaiornithidae is a group of early predatory enantiornithean dinosaurs from the early Cretaceous Period of China. All known specimens come from the Jiufotang Formation and Yixian Formation, dating to the early Aptian age, 125–120 million years ago. Bohaiornithidae was first coined by Wang and colleagues in 2014. They defined it as the natural group formed by all descendants of the common ancestor of the type species, Bohaiornis guoi, and Shenqiornis mengi.
Longusunguis is an extinct genus of bohaiornithid enantiornithean dinosaur known from the Early Cretaceous of Liaoning Province, northeastern China. It contains a single species, Longusunguis kurochkini.
Pengornithidae is a group of early enantiornithines from the early Cretaceous Period of China, with the putative member Falcatakely possibly extending this clade's range into the Late Cretaceous of Madagascar, and several putative pengornithids also hail from this formation. Specimens of these animals have been found both in the Huajiying Formation and Jiufotang Formation of Liaoning and Hebei provinces, dating from the Hauterivian age to the Aptian age.
Dingavis is an extinct genus of ornithuromorph dinosaurs from the Early Cretaceous of present-day China. It contains a single species, D. longimaxilla.
Chiappeavis is a genus of enantiornithean bird from Early Cretaceous of northeastern China. The only species is Chiappeavis magnapremaxillo. Chiappeavis is classified within the family Pengornithidae. It is known from a single, almost complete skeleton including feather impressions discovered in the Jiufotang Formation of the Jehol Group. Long feathers formed a fan-shaped tail that was probably employed in flight.
Jingmai Kathleen O'Connor is a paleontologist who works as a curator at the Field Museum.
