Protopteryx Temporal range: Early Cretaceous, | |
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Fossil specimen, National Museum of Natural Science | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Clade: | Avialae |
Clade: | † Enantiornithes |
Order: | † Protopterygiformes Zhang & Zhou, 2006 |
Family: | † Protopterygidae Zhang & Zhou, 2006 |
Genus: | † Protopteryx Zhang & Zhou, 2000 |
Species: | †P. fengningensis |
Binomial name | |
†Protopteryx fengningensis Zhang & Zhou, 2000 | |
Protopteryx is an extinct bird and possibly the basalmost enantiornithean, from the Cretaceous period. [1] The type species is P. fengningensis. [2] It was first discovered in the Sichakou Member of the Yixian Formation or Huajiying Formation of Hebei Province, northern China, [3] dating from 131 Ma ago. [4] Protopteryx has been found in the Daibeigou formation, as well. [5] The name Protopteryx means "primitive feather": [6] "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. [7]
Protopteryx fossils show that they were roughly the same as a today's starling. [6] The adult body length of Protopteryx was about 10 centimetres (3.9 in), excluding the tail feathers. Protopteryx teeth were conical and unserrated, and some teeth had a resorption pit similar to those seen in Archaeopteryx . The body of Protopteryx was covered in three types of feathers: down feathers, flight feathers, and long, ribbon-like tail feathers. The body was mostly covered in feathers of about 12 millimetres (0.47 in). The barbs of the down feathers were laminar instead of hairlike and were frayed at the tips. The most distinctive feature of Protopteryx is that the tail consisted of two long feathers which only had barbs at their tips. Closer to the body, the long tail feathers were thin and needle-like. The only modern bird to share a feather type similar to Protopteryx is the red bird-of-paradise. The tail feathers also lack rami on the proximal end of the tail. [8]
Protopteryx is one of the most basal known members of the group Enantiornithes. It appeared after Archaeopteryx, one of the most basal birds, and Confuciusornis . [9] Protopteryx is more basal than the species Eocathayornis [1] and Paraprotopteryx . [10]
Protopteryx was discovered in the Sichakou Member of the Hebei province, west of the Liaoning province. [11] The formations where Protopteryx was found were the Yixian and Dageibou formations. [12] [13] The Sichakou Basin is part of the Daxinganling-Taihangshan Tectonomagmatic Belt and moves in a north-northeast direction. When Protopteryx was alive, the Sichakou basin was located at the Hongqiangou-Jiecangou. [11]
Protopteryx lived in the Jehol Biota in the Cretaceous period, which contains many of the terrestrial and freshwater vertebrate clades. [14] The teeth of the Protopteryx are similar to Archaeopteryx, suggesting a similar diet. [8]
Protopteryx was adapted for flying and had feathers with features similar to modern birds, as shown by its procoracoid, carina of the sternum, external tuberosity of the humerus, and deltoid crest, which suggest Protopteryx had a modern musculus supercoracoideus and pectoralis. Protopteryx also shares asymmetric wing flight feathers with flying birds, as well as Archaeopteryx and Confuciusornis . [8] The tail feathers of Protopteryx lack of barbs and rami close to the body, [8] suggesting a use outside of flight, such as display, thermoregulation, or sensory usage. [9]
The alula, or bastard wing, is a small projection on the anterior edge of the wing of modern birds and a few non-avian dinosaurs. The word is Latin and means "winglet"; it is the diminutive of ala, meaning "wing". The alula is the freely moving first digit, a bird's "thumb", and typically bears three to five small flight feathers, with the exact number depending on the species. There also are minor covert feathers overlying the flight feathers. Like the larger flight feathers found on the wing's trailing edge, these alula feathers are asymmetrical, with the shaft running closer to anterior edge.
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.
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.
Sapeornis is a monotypic genus of avialan which lived during the early Cretaceous period. Sapeornis contains only one species, Sapeornis chaoyangensis.
Vescornis is a genus of enantiornithine bird. One species is named, V. hebeiensis. The holotype fossil is in the collection of the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences. Its catalog number is CAGS 130722. The fossil was found in Early Cretaceous rocks first attributed to the Yixian Formation, Senjitu, Fengning County, Hebei Province, China. However, later study of area geology showed that these rocks actually belong to the Huajiying Formation.
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.
Ornithothoraces is a group of avialans that includes all enantiornithes and the euornithes, which includes modern birds and their closest ancestors. The name Ornithothoraces means "bird thoraxes". This refers to the modern, highly advanced anatomy of the thorax that gave the ornithothoracines superior flight capability compared with more primitive avialans. This anatomy includes a large, keeled breastbone, elongated coracoids and a modified glenoid joint in the shoulder, and a semi-rigid rib cage. In spite of this at least the sternum seems to have developed convergently rather than being a true homology.
Pygostylia is a group of avialans which includes the Confuciusornithidae and all of the more advanced species, the Ornithothoraces.
The Jehol Biota includes all the living organisms – the ecosystem – of northeastern China between 133 and 120 million years ago. This is the Lower Cretaceous ecosystem which left fossils in the Yixian Formation and Jiufotang Formation. These deposits are composed of layers of tephra and sediment. It is also believed to have left fossils in the Sinuiju series of North Korea. The ecosystem in the Lower Cretaceous was dominated by wetlands and numerous lakes. Rainfall was seasonal, alternating between semiarid and mesic conditions. The climate was temperate. The Jehol ecosystem was interrupted periodically by ash eruptions from volcanoes to the west. The word "Jehol" is a historical transcription of the former Rehe Province.
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.
Jibeinia is a genus of enantiornithean bird. Only one species has been named, Jibeinia luanhera. It is known from one holotype fossil found in the Hebei province, People's Republic of China. This fossil is now lost. The holotype was, however, described and figured in detail by Hou (1997).
Eoconfuciusornis a genus of extinct avialan that lived 131 Ma ago, in the Early Cretaceous of China. It is the oldest known bird to have a beak.
The Huajiying Formation is a geological formation in Hebei, People's Republic of China. Known for its fossils including feathered dinosaurs, the age of the formation is uncertain. It may represent an early portion of the Jehol Biota, dating to somewhere in the early Cretaceous or late Jurassic periods. It may correlate with the early Cretaceous Dadianzi Formation and parts of the Yixian Formation, with an age range between 140 and 122 Ma ago. It contains the Qiaotou Member, sometimes treated as a distinct formation.
Shenqiornis is a bird genus of the Enantiornithes. It was found in the Qiaotou Member of the Huajiying Formation of Hebei Province, China, and is therefore of uncertain age. The Qiaotou Member may correlate with the more well-known Early Cretaceous Yixian Formation, and so probably is dated to the Aptian, around 122 million years ago.
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.
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.