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.
Yanornis is an extinct genus of fish-eating Early Cretaceous birds. Two species have been described, both from Liaoning province, China: Yanornis martini, based on several fossils found in the 120-million-year-old Jiufotang Formation at Chaoyang, and Yanornis guozhangi, from the 124-million-year-old Yixian Formation.
Longipteryx is a genus of prehistoric bird which lived during the Early Cretaceous. It contains a single species, Longipteryx chaoyangensis. Its remains have been recovered from the Jiufotang Formation at Chaoyang in Liaoning Province, China. Apart from the holotype IVPP V 12325 - a fine and nearly complete skeleton — another entire skeleton and some isolated bones are known to date.
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.
Boluochia zhengi was an enantiornithine bird. It lived during the Early Cretaceous in the time span 121.6-110.6 mya and is known from fossils found in the Jiufotang Formation of Liaoning province, People's Republic of China. Boluochia was first described by Zhou in 1995. A re-analysis of the specimen by Jingmai O'Connor and colleagues found that it was closely related to Longipteryx and could be assigned to the family Longipterygidae.
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.
Yixianornis is a bird genus from the early Cretaceous period. Its remains have been found in the Jiufotang Formation at Chaoyang dated to the early Aptian age, around 120 million years ago. Only one species, Yixianornis grabaui, is known at present. The specific name, grabaui, is named after American paleontologist Amadeus William Grabau, who surveyed China in the early 20th century.
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.
Paraprotopteryx is a genus of enantiornithean birds from the Mesozoic of China.
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.
Hongshanornithidae is an extinct group of early ornithuromorph birds from the early Cretaceous period of China. It includes the genera Hongshanornis and Tianyuornis from the Yixian Formation of Inner Mongolia, Longicrusavis from the Yixian Formation of Liaoning Province, Parahongshanornis from the Jiufotang Formation of Liaoning Province, and Archaeornithura, the oldest known member, from the Huajiying Formation of Hebei Province.
Dalingheornis is a genus of enantiornithean birds which lived during the early Cretaceous period, about 122 Ma ago, and are known from a single juvenile fossil found in the upper part of the Yixian Formation at Dawangzhangzi, Liaoning province, People's Republic of China. It is the first known Mesozoic bird with heterodactyl feet specifically adapted for climbing, and was probably among the most arboreal of the enantiornithines. Unlike its relatives, it had an unusually long (17mm) skeletal tail made up of 20 vertebrae, similar to the tails of dromaeosaurids. However, this may have been a juvenile feature. The fossil was named after Yang Liwei, the first Chinese astronaut in space.
Songlingornithidae is a family of basal euornithean dinosaurs from the Early Cretaceous of China. All known specimens come from the Jiufotang Formation and the Yixian Formation, dating to the early Barremian and Aptian ages, 125–120 million years ago.
Bohaiornis is a genus of enantiornithean dinosaurs. Fossils have been found from the Lower Cretaceous Jiufotang Formation of western Liaoning, China. The only known species, Bohaiornis guoi, was named by Dongyu Hu, Li Li, Lianhaim Hou and Xing Xu in 2011 on the basis of a fully articulated and well-preserved skeleton of a sub-adult. This specimen, LPM B00167, preserved two long, ribbon-like feathers attached to the tail rather than a fan of shorter pennaceous feathers. It was similar to the slightly older Eoenantiornis, but much larger in size. Bohaiornis is the type species of Bohaiornithidae, a family of large predatory enantiornitheans from the Early Cretaceous.
Shengjingornis is a genus of enantiornithean bird known from the Early Cretaceous of Jinzhou, western Liaoning, China. Its remains were discovered in Jiufotang Formation deposits, dated to 120 million years ago.
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.
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.
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.
