92-498: Columba inornata Vigors, 1827 The plain pigeon ( Patagioenas inornata ) is a species of bird in the family Columbidae . It is found in the four Greater Antilles : Cuba , Hispaniola (in the Dominican Republic and Haiti ), Jamaica , and Puerto Rico . Its natural habitats are forest, woodland, coastal desert, mangrove and swampy areas. It is threatened by habitat loss and illegal hunting. The plain pigeon
184-498: A 2013 study published in the Journal of Analytical Atomic Spectrometry , new analyses of Archaeopteryx ' s feathers revealed that the animal may have had complex light- and dark-coloured plumage, with heavier pigmentation in the distal tips and outer vanes. This analysis of colour distribution was based primarily on the distribution of sulphate within the fossil. An author on the previous Archaeopteryx colour study argued against
276-876: A better sense of smell. A third stage of bird evolution starting with Ornithothoraces (the "bird-chested" avialans) can be associated with the refining of aerodynamics and flight capabilities, and the loss or co-ossification of several skeletal features. Particularly significant are the development of an enlarged, keeled sternum and the alula , and the loss of grasping hands. † Anchiornis † Archaeopteryx † Xiaotingia † Rahonavis † Jeholornis † Jixiangornis † Balaur † Zhongjianornis † Sapeornis † Confuciusornithiformes † Protopteryx † Pengornis Ornithothoraces † Enantiornithes Archaeopteryx Archaeopteryx ( / ˌ ɑːr k iː ˈ ɒ p t ər ɪ k s / ; lit. ' old-wing ' ), sometimes referred to by its German name, " Urvogel " ( lit. Primeval Bird )
368-652: A complete absence of air bubbles in the rock slabs is further proof that the specimen is authentic. Most of the specimens of Archaeopteryx that have been discovered come from the Solnhofen limestone in Bavaria, southern Germany, which is a Lagerstätte , a rare and remarkable geological formation known for its superbly detailed fossils laid down during the early Tithonian stage of the Jurassic period, approximately 150.8–148.5 million years ago. Archaeopteryx
460-490: A constricted portion of the crown in some teeth and a stouter metatarsus. A supposed additional species, Wellnhoferia grandis (based on the Solnhofen specimen), seems to be indistinguishable from A. lithographica except in its larger size. If two names are given, the first denotes the original describer of the "species", the second the author on whom the given name combination is based. As always in zoological nomenclature , putting an author's name in parentheses denotes that
552-473: A definition similar to "all theropods closer to birds than to Deinonychus ", with Troodon being sometimes added as a second external specifier in case it is closer to birds than to Deinonychus . Avialae is also occasionally defined as an apomorphy-based clade (that is, one based on physical characteristics). Jacques Gauthier , who named Avialae in 1986, re-defined it in 2001 as all dinosaurs that possessed feathered wings used in flapping flight , and
644-416: A dorsal covert , which would have partly covered the primary feathers on the wings. The study does not mean that Archaeopteryx was entirely black, but suggests that it had some black colouration which included the coverts. Carney pointed out that this is consistent with what is known of modern flight characteristics, in that black melanosomes have structural properties that strengthen feathers for flight. In
736-434: A forgery was based on unfamiliarity with the processes of lithification ; for example, they proposed that, based on the difference in texture associated with the feathers, feather impressions were applied to a thin layer of cement , without realizing that feathers themselves would have caused a textural difference. They also misinterpreted the fossils, claiming that the tail was forged as one large feather, when visibly this
828-442: A group called Paraves . Some basal members of Deinonychosauria, such as Microraptor , have features which may have enabled them to glide or fly. The most basal deinonychosaurs were very small. This evidence raises the possibility that the ancestor of all paravians may have been arboreal , have been able to glide, or both. Unlike Archaeopteryx and the non-avialan feathered dinosaurs, who primarily ate meat, studies suggest that
920-439: A high metabolic rate, a four-chambered heart , and a strong yet lightweight skeleton . Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich . There are over 11,000 living species and they are split into 44 orders . More than half are passerine or "perching" birds. Birds have wings whose development varies according to species;
1012-438: A key piece of evidence for the origin of birds, the transitional fossils debate, and confirmation of evolution . Archaeopteryx was long considered to be the beginning of the evolutionary tree of birds. However, in recent years, the discovery of several small, feathered dinosaurs has created a mystery for palaeontologists, raising questions about which animals are the ancestors of modern birds and which are their relatives. Over
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#17327827985731104-780: A private collection in Switzerland, the Thermopolis Specimen (WDC CSG 100) was discovered in Bavaria and described in 2005 by Mayr, Pohl, and Peters. Donated to the Wyoming Dinosaur Center in Thermopolis, Wyoming , it has the best-preserved head and feet; most of the neck and the lower jaw have not been preserved. The "Thermopolis" specimen was described on 2 December 2005 Science journal article as "A well-preserved Archaeopteryx specimen with theropod features"; it shows that Archaeopteryx lacked
1196-473: A reversed toe—a universal feature of birds—limiting its ability to perch on branches and implying a terrestrial or trunk-climbing lifestyle. This has been interpreted as evidence of theropod ancestry. In 1988, Gregory S. Paul claimed to have found evidence of a hyperextensible second toe, but this was not verified and accepted by other scientists until the Thermopolis specimen was described. "Until now,
1288-485: A single feather which appeared to resemble a modern bird's remex (wing feather), but he had heard of and been shown a rough sketch of the London specimen, to which he referred as a " Skelett eines mit ähnlichen Federn bedeckten Tieres " ("skeleton of an animal covered in similar feathers"). In German, this ambiguity is resolved by the term Schwinge which does not necessarily mean a wing used for flying. Urschwinge
1380-593: A single species, although this is still debated. Most of these twelve fossils include impressions of feathers. Because these feathers are of an advanced form ( flight feathers ), these fossils are evidence that the evolution of feathers began before the Late Jurassic. The type specimen of Archaeopteryx was discovered just two years after Charles Darwin published On the Origin of Species . Archaeopteryx seemed to confirm Darwin's theories and has since become
1472-406: A sister group, the order Crocodilia , contain the only living representatives of the reptile clade Archosauria . During the late 1990s, Aves was most commonly defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica . However, an earlier definition proposed by Jacques Gauthier gained wide currency in the 21st century, and
1564-717: A time, sometimes for years, and rarely for life. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction . They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching. Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Songbirds , parrots, and other species are popular as pets. Guano (bird excrement)
1656-608: A torso, the Maxberg Specimen (S5) was discovered in 1956 near Langenaltheim ; it was brought to the attention of professor Florian Heller in 1958 and described by him in 1959. The specimen is missing its head and tail, although the rest of the skeleton is mostly intact. Although it was once exhibited at the Maxberg Museum in Solnhofen , it is currently missing. It belonged to Eduard Opitsch , who loaned it to
1748-534: Is a genus of bird -like dinosaurs . The name derives from the ancient Greek ἀρχαῖος ( archaīos ), meaning "ancient", and πτέρυξ ( ptéryx ), meaning "feather" or "wing". Between the late 19th century and the early 21st century, Archaeopteryx was generally accepted by palaeontologists and popular reference books as the oldest known bird (member of the group Avialae ). Older potential avialans have since been identified, including Anchiornis , Xiaotingia , and Aurornis . Archaeopteryx lived in
1840-408: Is a large-bodied bird (38 cm [15 in]) that superficially resembles the common city pigeon . At a distance it appears pale blue-gray overall. The head, hindneck, breast, and part of the folded wing are colored with a red-wine wash. When folded, the wing shows a white leading edge; in flight , it forms a conspicuous wing bar. Legs and feet are dark red. The female is slightly smaller and duller than
1932-540: Is called ornithology . Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs . Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians . Birds are descendants of the primitive avialans (whose members include Archaeopteryx ) which first appeared during the Late Jurassic . According to recent estimates, modern birds ( Neornithes ) evolved in
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#17327827985732024-429: Is harvested for use as a fertiliser. Birds figure throughout human culture. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry. The first classification of birds
2116-509: Is missing much of the skull and one forelimb. It is privately owned and has yet to be given a name. Palaeontologists of the Ludwig Maximilian University of Munich studied the specimen, which revealed previously unknown features of the plumage, such as feathers on both the upper and lower legs and metatarsus , and the only preserved tail tip. A twelfth specimen had been discovered by an amateur collector in 2010 at
2208-503: Is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. Over 40% of key traits found in modern birds evolved during the 60 million year transition from the earliest bird-line archosaurs to the first maniraptoromorphs , i.e. the first dinosaurs closer to living birds than to Tyrannosaurus rex . The loss of osteoderms otherwise common in archosaurs and acquisition of primitive feathers might have occurred early during this phase. After
2300-496: Is not the case. In addition, they claimed that the other specimens of Archaeopteryx known at the time did not have feathers, which is incorrect; the Maxberg and Eichstätt specimens have obvious feathers. They also expressed disbelief that slabs would split so smoothly, or that one half of a slab containing fossils would have good preservation, but not the counterslab . These are common properties of Solnhofen fossils, because
2392-516: Is synonymous to Avifilopluma. † Scansoriopterygidae † Eosinopteryx † Jinfengopteryx † Aurornis † Dromaeosauridae † Troodontidae Avialae Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of theropod dinosaurs and, more specifically, members of Maniraptora , a group of theropods which includes dromaeosaurids and oviraptorosaurs , among others. As scientists have discovered more theropods closely related to birds,
2484-458: Is that Owen wanted to set a trap for Darwin, hoping the latter would support the fossils so Owen could discredit him with the forgery; this is unlikely because Owen wrote a detailed paper on the London specimen, so such an action would certainly backfire. Charig et al. pointed to the presence of hairline cracks in the slabs running through both rock and fossil impressions, and mineral growth over
2576-560: Is to be studied by famed paleornithologist Jingmai O'Connor . Beginning in 1985, an amateur group including astronomer Fred Hoyle and physicist Lee Spetner , published a series of papers claiming that the feathers on the Berlin and London specimens of Archaeopteryx were forged. Their claims were repudiated by Alan J. Charig and others at the Natural History Museum in London . Most of their supposed evidence for
2668-535: Is used by many scientists including adherents to the PhyloCode . Gauthier defined Aves to include only the crown group of the set of modern birds. This was done by excluding most groups known only from fossils , and assigning them, instead, to the broader group Avialae, on the principle that a clade based on extant species should be limited to those extant species and their closest extinct relatives. Gauthier and de Queiroz identified four different definitions for
2760-598: The Archaeopteryx , with a long lizard-like tail, bearing a pair of feathers on each joint, and with its wings furnished with two free claws, has been discovered in the oolitic slates of Solnhofen. Hardly any recent discovery shows more forcibly than this how little we as yet know of the former inhabitants of the world." The Greek word archaīos ( ἀρχαῖος ) means 'ancient, primeval'. Ptéryx primarily means 'wing', but it can also be just 'feather'. Meyer suggested this in his description. At first he referred to
2852-663: The Field Museum in Chicago, US. One of two specimens in an institution outside Europe, the specimen was originally identified in a private collection in Switzerland , and had been acquired by these collectors in 1990, prior to Germany's 2015 ban on exporting Archaeopteryx specimens. The specimen was acquired by the Field Museum in 2022, and went on public display in 2024 following two years of preparation. The specimen
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2944-605: The Jura Museum in Eichstätt, Germany, it is the smallest known specimen and has the second-best head. It is possibly a separate genus ( Jurapteryx recurva ) or species ( A. recurva ). The Solnhofen Specimen (unnumbered specimen) was discovered in the 1970s near Eichstätt, Germany, and described in 1988 by Wellnhofer. Currently located at the Bürgermeister-Müller-Museum in Solnhofen, it originally
3036-722: The Late Cretaceous and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non- ornithuran dinosaurs. Many social species preserve knowledge across generations ( culture ). Birds are social, communicating with visual signals, calls, and songs , and participating in such behaviour as cooperative breeding and hunting, flocking , and mobbing of predators. The vast majority of bird species are socially (but not necessarily sexually) monogamous , usually for one breeding season at
3128-638: The Late Jurassic around 150 million years ago, in what is now southern Germany, during a time when Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now. Similar in size to a Eurasian magpie , with the largest individuals possibly attaining the size of a raven , the largest species of Archaeopteryx could grow to about 0.5 m (1 ft 8 in) in length. Despite their small size, broad wings, and inferred ability to fly or glide, Archaeopteryx had more in common with other small Mesozoic dinosaurs than with modern birds. In particular, they shared
3220-476: The London Specimen (BMNH 37001), was unearthed in 1861 near Langenaltheim , Germany, and perhaps given to local physician Karl Häberlein in return for medical services. He then sold it for £700 (roughly £83,000 in 2020 ) to the Natural History Museum in London, where it remains. Missing most of its head and neck, it was described in 1863 by Richard Owen as Archaeopteryx macrura , allowing for
3312-669: The Tiaojishan Formation of China, which has been dated to the late Jurassic period ( Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi , Xiaotingia zhengi , and Aurornis xui . The well-known probable early avialan, Archaeopteryx , dates from slightly later Jurassic rocks (about 155 million years old) from Germany . Many of these early avialans shared unusual anatomical features that may be ancestral to modern birds but were later lost during bird evolution. These features include enlarged claws on
3404-413: The ankle bone , interdental plates , an obturator process of the ischium , and long chevrons in the tail. In particular, Ostrom found that Archaeopteryx was remarkably similar to the theropod family Dromaeosauridae . Archaeopteryx had three separate digits on each fore-leg each ending with a "claw". Few birds have such features. Some birds, such as ducks , swans , Jacanas ( Jacana sp.), and
3496-408: The hoatzin ( Opisthocomus hoazin ), have them concealed beneath their leg-feathers. Specimens of Archaeopteryx were most notable for their well-developed flight feathers . They were markedly asymmetrical and showed the structure of flight feathers in modern birds, with vanes given stability by a barb - barbule - barbicel arrangement. The tail feathers were less asymmetrical, again in line with
3588-399: The 1970s, John Ostrom , following Thomas Henry Huxley 's lead in 1868, argued that birds evolved within theropod dinosaurs and Archaeopteryx was a critical piece of evidence for this argument; it had several avian features, such as a wishbone, flight feathers, wings, and a partially reversed first toe along with dinosaur and theropod features. For instance, it has a long ascending process of
3680-557: The ICZN after four years of debate, and the London specimen was designated the neotype on 3 October 2011. Below is a cladogram published in 2013 by Godefroit et al. Aurornis [REDACTED] Anchiornis [REDACTED] Archaeopteryx [REDACTED] Xiaotingia [REDACTED] Jeholornis [REDACTED] Rahonavis [REDACTED] Balaur [REDACTED] Avebrevicauda (includes modern birds) [REDACTED] It has been argued that all
3772-420: The London specimen was the holotype . In 1960, Swinton accordingly proposed that the name Archaeopteryx lithographica be placed on the official genera list making the alternative names Griphosaurus and Griphornis invalid. The ICZN , implicitly accepting De Beer's standpoint, did indeed suppress the plethora of alternative names initially proposed for the first skeleton specimens, which mainly resulted from
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3864-551: The Netherlands. It was the very first specimen found, but was incorrectly classified at the time. It is also one of the least complete specimens, consisting mostly of limb bones, isolated cervical vertebrae, and ribs. In 2017 it was named as a separate genus Ostromia , considered more closely related to Anchiornis from China. The Eichstätt Specimen (JM 2257) was discovered in 1951 near Workerszell , Germany, and described by Peter Wellnhofer in 1974. Currently located at
3956-650: The Schamhaupten quarry, but the finding was only announced in February 2014. It was scientifically described in 2018. It represents a complete and mostly articulated skeleton with skull. It is the only specimen lacking preserved feathers. It is from the Painten Formation and somewhat older than the other specimens. The existence of a thirteenth specimen (the Chicago specimen ) was announced in 2024 by
4048-603: The acrimonious dispute between Meyer and his opponent Johann Andreas Wagner (whose Griphosaurus problematicus —'problematic riddle -lizard'—was a vitriolic sneer at Meyer's Archaeopteryx ). In addition, in 1977, the Commission ruled that the first species name of the Haarlem specimen, crassipes , described by Meyer as a pterosaur before its true nature was realized, was not to be given preference over lithographica in instances where scientists considered them to represent
4140-428: The appearance of Maniraptoromorpha, the next 40 million years marked a continuous reduction of body size and the accumulation of neotenic (juvenile-like) characteristics. Hypercarnivory became increasingly less common while braincases enlarged and forelimbs became longer. The integument evolved into complex, pennaceous feathers . The oldest known paravian (and probably the earliest avialan) fossils come from
4232-649: The basis for a distinct species, A. bavarica , but more recent studies suggest it belongs to A. siemensii . An eighth, fragmentary specimen was discovered in 1990 in the younger Mörnsheim Formation at Daiting , Suevia . Therefore, it is known as the Daiting Specimen , and had been known since 1996 only from a cast, briefly shown at the Naturkundemuseum in Bamberg . The original was purchased by palaeontologist Raimund Albertsdörfer in 2009. It
4324-509: The birds that descended from them. Despite being currently one of the most widely used, the crown-group definition of Aves has been criticised by some researchers. Lee and Spencer (1997) argued that, contrary to what Gauthier defended, this definition would not increase the stability of the clade and the exact content of Aves will always be uncertain because any defined clade (either crown or not) will have few synapomorphies distinguishing it from its closest relatives. Their alternative definition
4416-415: The company that bears his name. Described in 1884 by Wilhelm Dames , it is the most complete specimen, and the first with a complete head. In 1897 it was named by Dames as a new species, A. siemensii ; though often considered a synonym of A. lithographica , several 21st century studies have concluded that it is a distinct species which includes the Berlin, Munich, and Thermopolis specimens. Composed of
4508-467: The dead animals would fall onto hardened surfaces, which would form a natural plane for the future slabs to split along and would leave the bulk of the fossil on one side and little on the other. Finally, the motives they suggested for a forgery are not strong, and are contradictory; one is that Richard Owen wanted to forge evidence in support of Charles Darwin's theory of evolution, which is unlikely given Owen's views toward Darwin and his theory. The other
4600-665: The earliest members of Aves, is removed from this group, becoming a non-avian dinosaur instead. These proposals have been adopted by many researchers in the field of palaeontology and bird evolution , though the exact definitions applied have been inconsistent. Avialae, initially proposed to replace the traditional fossil content of Aves, is often used synonymously with the vernacular term "bird" by these researchers. † Coelurus † Ornitholestes † Ornithomimosauria † Alvarezsauridae † Oviraptorosauria Paraves Most researchers define Avialae as branch-based clade, though definitions vary. Many authors have used
4692-401: The feather had been designated the type specimen , the name Archaeopteryx should then no longer be applied to the skeletons, thus creating significant nomenclatorial confusion. In 2007, two sets of scientists therefore petitioned the ICZN requesting that the London specimen explicitly be made the type by designating it as the new holotype specimen, or neotype . This suggestion was upheld by
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#17327827985734784-411: The feather was described), and that the feather was inconsistent with the morphology of all other Archaeopteryx feathers known, leading to the conclusion that it originated from another dinosaur. This conclusion was challenged in 2020 as being unlikely; the feather was identified on the basis of morphology as most likely having been an upper major primary covert feather . The first skeleton, known as
4876-413: The feature was thought to belong only to the species' close relatives, the deinonychosaurs." The Thermopolis Specimen was assigned to Archaeopteryx siemensii in 2007. The specimen is considered to represent the most complete and best-preserved Archaeopteryx remains yet. The discovery of an eleventh specimen was announced in 2011; it was described in 2014. It is one of the more complete specimens, but
4968-451: The first avialans were omnivores . The Late Jurassic Archaeopteryx is well known as one of the first transitional fossils to be found, and it provided support for the theory of evolution in the late 19th century. Archaeopteryx was the first fossil to display both clearly traditional reptilian characteristics—teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers similar to those of modern birds. It
5060-478: The following features with the dromaeosaurids and troodontids : jaws with sharp teeth , three fingers with claws , a long bony tail, hyperextensible second toes ("killing claw"), feathers (which also suggest warm-bloodedness ), and various features of the skeleton . These features make Archaeopteryx a clear candidate for a transitional fossil between non-avian dinosaurs and avian dinosaurs (birds). Thus, Archaeopteryx plays an important role, not only in
5152-470: The interpretation of such biomarkers as an indicator of eumelanin in the full Archaeopteryx specimen. Carney and other colleagues also argued against the 2013 study's interpretation of the sulphate and trace metals, and in a 2020 study published in Scientific Reports demonstrated that the isolated covert feather was entirely matte black (as opposed to black and white, or iridescent) and that
5244-545: The male. Juveniles are browner overall, with pale wing margins and dark eyes. The plain pigeon is thought to represent a fairly recent island adaptation of the red-billed pigeon ( P. flavirostria ) or the Maranon pigeon ( P. oenops ), found in Central and South America. Three subspecies of the plain pigeon are recognized: During the 1970s, P. i. wetmorei was on the brink of extinction . A conservation program
5336-433: The money to buy a cow in 1876, to innkeeper Johann Dörr, who again sold it to Ernst Otto Häberlein, the son of K. Häberlein. Placed on sale between 1877 and 1881, with potential buyers including O. C. Marsh of Yale University 's Peabody Museum, it eventually was bought for 20,000 Goldmark by the Berlin's Natural History Museum, where it now is displayed. The transaction was financed by Ernst Werner von Siemens , founder of
5428-616: The museum until 1974. After his death in 1991, it was discovered that the specimen was missing and may have been stolen or sold. The Haarlem Specimen (TM 6428/29, also known as the Teylers Specimen ) was discovered in 1855 near Riedenburg , Germany, and described as a Pterodactylus crassipes in 1857 by Meyer. It was reclassified in 1970 by John Ostrom and is currently located at the Teylers Museum in Haarlem ,
5520-523: The only known groups without wings are the extinct moa and elephant birds . Wings, which are modified forelimbs , gave birds the ability to fly, although further evolution has led to the loss of flight in some birds , including ratites , penguins , and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds , have further evolved for swimming. The study of birds
5612-431: The other feather-bearing specimens, which have increased in number since then. Charig et al. reported a discolouration: a dark band between two layers of limestone – they say it is the product of sedimentation. It is natural for limestone to take on the colour of its surroundings and most limestones are coloured (if not colour banded) to some degree, so the darkness was attributed to such impurities. They also mention that
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#17327827985735704-402: The outermost half) can be seen in the evolution of maniraptoromorphs, and this process culminated in the appearance of the pygostyle , an ossification of fused tail vertebrae. In the late Cretaceous, about 100 million years ago, the ancestors of all modern birds evolved a more open pelvis, allowing them to lay larger eggs compared to body size. Around 95 million years ago, they evolved
5796-473: The point of embedding in the sediment. So it is hypothesized that the pertinent specimens moved along the sea bed in shallow water for some time before burial, the head and upper neck feathers sloughing off, while the more firmly attached tail feathers remained. In 2011, graduate student Ryan Carney and colleagues performed the first colour study on an Archaeopteryx specimen. Using scanning electron microscopy technology and energy-dispersive X-ray analysis,
5888-454: The possibility it did not belong to the same species as the feather. In the subsequent fourth edition of his On the Origin of Species , Charles Darwin described how some authors had maintained "that the whole class of birds came suddenly into existence during the eocene period; but now we know, on the authority of Professor Owen, that a bird certainly lived during the deposition of the upper greensand; and still more recently, that strange bird,
5980-488: The possible presence of a sternum . Due to these differences, most individual specimens have been given their own species name at one point or another. The Berlin specimen has been designated as Archaeornis siemensii , the Eichstätt specimen as Jurapteryx recurva , the Munich specimen as Archaeopteryx bavarica , and the Solnhofen specimen as Wellnhoferia grandis . In 2007, a review of all well-preserved specimens including
6072-410: The presence of cement on the London specimen through X-ray spectroscopy , and did find something that was not rock; it was not cement either, and is most probably a fragment of silicone rubber left behind when moulds were made of the specimen. Their suggestions have not been taken seriously by palaeontologists, as their evidence was largely based on misunderstandings of geology, and they never discussed
6164-414: The presence of numerous avian features, Archaeopteryx had many non-avian theropod dinosaur characteristics. Unlike modern birds, Archaeopteryx had small teeth, as well as a long bony tail, features which Archaeopteryx shared with other dinosaurs of the time. Because it displays features common to both birds and non-avian dinosaurs, Archaeopteryx has often been considered a link between them. In
6256-536: The previously clear distinction between non-birds and birds has become blurred. By the 2000s, discoveries in the Liaoning Province of northeast China, which demonstrated many small theropod feathered dinosaurs , contributed to this ambiguity. The consensus view in contemporary palaeontology is that the flying theropods, or avialans , are the closest relatives of the deinonychosaurs , which include dromaeosaurids and troodontids . Together, these form
6348-454: The remainder of the body—although some feathers did not fossilize and others were obliterated during preparation, leaving bare patches on specimens—and the lower neck. There is no indication of feathering on the upper neck and head. While these conceivably may have been nude, this may still be an artefact of preservation. It appears that most Archaeopteryx specimens became embedded in anoxic sediment after drifting some time on their backs in
6440-448: The remaining "plumage patterns of Archaeopteryx remain unknown". Today, fossils of the genus Archaeopteryx are usually assigned to one or two species, A. lithographica and A. siemensii , but their taxonomic history is complicated. Ten names have been published for the handful of specimens. As interpreted today, the name A. lithographica only referred to the single feather described by Meyer . In 1954 Gavin de Beer concluded that
6532-403: The rest of the species of Archaeopteryx . In the Berlin specimen, there are "trousers" of well-developed feathers on the legs; some of these feathers seem to have a basic contour feather structure, but are somewhat decomposed (they lack barbicels as in ratites ). In part they are firm and thus capable of supporting flight. A patch of pennaceous feathers is found running along its back, which
6624-452: The same biological name "Aves", which is a problem. The authors proposed to reserve the term Aves only for the crown group consisting of the last common ancestor of all living birds and all of its descendants, which corresponds to meaning number 4 below. They assigned other names to the other groups. Lizards & snakes Turtles Crocodiles Birds Under the fourth definition Archaeopteryx , traditionally considered one of
6716-404: The same species. It has been noted that the feather, the first specimen of Archaeopteryx described, does not correspond well with the flight-related feathers of Archaeopteryx . It certainly is a flight feather of a contemporary species, but its size and proportions indicate that it may belong to another, smaller species of feathered theropod , of which only this feather is known so far. As
6808-430: The sea—the head, neck and the tail are generally bent downward, which suggests that the specimens had just started to rot when they were embedded, with tendons and muscle relaxing so that the characteristic shape ( death pose ) of the fossil specimens was achieved. This would mean that the skin already was softened and loose, which is bolstered by the fact that in some specimens the flight feathers were starting to detach at
6900-551: The second toe which may have been held clear of the ground in life, and long feathers or "hind wings" covering the hind limbs and feet, which may have been used in aerial maneuvering. Avialans diversified into a wide variety of forms during the Cretaceous period. Many groups retained primitive characteristics , such as clawed wings and teeth, though the latter were lost independently in a number of avialan groups, including modern birds (Aves). Increasingly stiff tails (especially
6992-408: The situation in modern birds and also had firm vanes. The thumb did not yet bear a separately movable tuft of stiff feathers . The body plumage of Archaeopteryx is less well-documented and has only been properly researched in the well-preserved Berlin specimen . Thus, as more than one species seems to be involved, the research into the Berlin specimen's feathers does not necessarily hold true for
7084-400: The slabs that had occurred before discovery and preparation, as evidence that the feathers were original. Spetner et al. then attempted to show that the cracks would have propagated naturally through their postulated cement layer, but neglected to account for the fact that the cracks were old and had been filled with calcite , and thus were not able to propagate. They also attempted to show
7176-505: The specimens belong to the same species, A. lithographica . Differences do exist among the specimens, and while some researchers regard these as due to the different ages of the specimens, some may be related to actual species diversity. In particular, the Munich, Eichstätt, Solnhofen, and Thermopolis specimens differ from the London, Berlin, and Haarlem specimens in being smaller or much larger, having different finger proportions, having more slender snouts lined with forward-pointing teeth, and
7268-426: The study of the origin of birds , but in the study of dinosaurs. It was named from a single feather in 1861, the identity of which has been controversial. That same year, the first complete specimen of Archaeopteryx was announced. Over the years, eleven more fossils of Archaeopteryx have surfaced. Despite variation among these fossils, most experts regard all the remains that have been discovered as belonging to
7360-407: The team was able to detect the structure of melanosomes in the isolated feather specimen described in 1861. The resultant measurements were then compared to those of 87 modern bird species, and the original colour was calculated with a 95% likelihood to be black. The feather was determined to be black throughout, with heavier pigmentation in the distal tip. The feather studied was most probably
7452-510: The then-newly discovered Thermopolis specimen concluded that two distinct species of Archaeopteryx could be supported: A. lithographica (consisting of at least the London and Solnhofen specimens), and A. siemensii (consisting of at least the Berlin, Munich, and Thermopolis specimens). The two species are distinguished primarily by large flexor tubercles on the foot claws in A. lithographica (the claws of A. siemensii specimens being relatively simple and straight). A. lithographica also had
7544-469: The years, twelve body fossil specimens of Archaeopteryx have been found. All of the fossils come from the limestone deposits, quarried for centuries, near Solnhofen , Germany. These quarries excavate sediments from the Solnhofen Limestone formation and related units. The initial specimen was the first dinosaur to be discovered with feathers. The initial discovery, a single feather,
7636-487: Was classified as Compsognathus by an amateur collector, the same mayor Friedrich Müller after which the museum is named. It is the largest specimen known and may belong to a separate genus and species, Wellnhoferia grandis . It is missing only portions of the neck, tail, backbone, and head. The Munich Specimen (BSP 1999 I 50, formerly known as the Solenhofer-Aktien-Verein Specimen )
7728-466: Was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae . Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use. Birds are categorised as the biological class Aves in Linnaean taxonomy . Phylogenetic taxonomy places Aves in the clade Theropoda as an infraclass or a subclass, more recently a subclass. Aves and
7820-516: Was discovered on 3 August 1992 near Langenaltheim and described in 1993 by Wellnhofer. It is currently located at the Paläontologisches Museum München in Munich, to which it was sold in 1999 for 1.9 million Deutschmark . What was initially believed to be a bony sternum turned out to be part of the coracoid , but a cartilaginous sternum may have been present. Only the front of its face is missing. It has been used as
7912-579: Was found in 2000. It is in private possession and, since 2004, on loan to the Bürgermeister-Müller Museum in Solnhofen, so it is called the Bürgermeister-Müller Specimen ; the institute itself officially refers to it as the "Exemplar of the families Ottman & Steil, Solnhofen". As the fragment represents the remains of a single wing of Archaeopteryx , it is colloquially known as "chicken wing". Long in
8004-410: Was introduced to save the species and now it numbers a few thousand individuals. This Columbiformes -related article is a stub . You can help Misplaced Pages by expanding it . Bird Birds are a group of warm-blooded vertebrates constituting the class Aves ( Latin: [ˈaveːs] ), characterised by feathers , toothless beaked jaws, the laying of hard-shelled eggs,
8096-665: Was on display for the first time with six other original fossils of Archaeopteryx at the Munich Mineral Show in October 2009. The Daiting Specimen was subsequently named Archaeopteryx albersdoerferi by Kundrat et al. (2018). After a lengthy period in a closed private collection, it was moved to the Museum of Evolution at Knuthenborg Safaripark (Denmark) in 2022, where it has since been on display and also been made available for researchers. Another fragmentary fossil
8188-476: Was quite similar to the contour feathers of the body plumage of modern birds in being symmetrical and firm, although not as stiff as the flight-related feathers. Apart from that, the feather traces in the Berlin specimen are limited to a sort of "proto- down " not dissimilar to that found in the dinosaur Sinosauropteryx : decomposed and fluffy, and possibly even appearing more like fur than feathers in life (although not in their microscopic structure). These occur on
8280-461: Was roughly the size of a raven , with broad wings that were rounded at the ends and a long tail compared to its body length. It could reach up to 0.5 metres (1 ft 8 in) in body length and 0.7 metres (2 ft 4 in) in wingspan , with an estimated mass of 0.5 to 1 kilogram (1.1 to 2.2 lb). Archaeopteryx feathers, although less documented than its other features, were very similar in structure to modern-day bird feathers. Despite
8372-514: Was the favoured translation of Archaeopteryx among German scholars in the late nineteenth century. In English, 'ancient pinion' offers a rough approximation to this. Since then, twelve specimens have been recovered: The Berlin Specimen (HMN 1880/81) was discovered in 1874 or 1875 on the Blumenberg near Eichstätt , Germany, by farmer Jakob Niemeyer. He sold this precious fossil for
8464-411: Was unearthed in 1860 or 1861 and described in 1861 by Hermann von Meyer . It is currently located at the Natural History Museum of Berlin . Though it was the initial holotype , there were indications that it might not have been from the same animal as the body fossils. In 2019 it was reported that laser imaging had revealed the structure of the quill (which had not been visible since some time after
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