Misplaced Pages

#602397

116-588: 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 Formation in Hebei Province , China (in what was previously Rehe Province , also known as Jehol—hence the name) and additional specimens have been found in

232-566: A junior objective synonym of Archaeoraptor liaoningensis and the latter, if valid, would have had priority under the International Code of Zoological Nomenclature . However, there is some doubt whether Olson in fact succeeded in meeting all the formal requirements for establishing a new taxon. Namely, Olson designated the specimen as a lectotype , before an actual type species was formally erected. A similar situation arose with Tyrannosaurus rex and Manospondylus gigas , in which

348-525: A "four-winged dinosaur" and to speculate that it may have glided using all four limbs for lift. Subsequent studies have suggested that Microraptor was capable of powered flight as well. Microraptor was among the most abundant non- avialan dinosaurs in its ecosystem, and the genus is represented by more fossils than any other dromaeosaurid, with possibly over 300 fossil specimens represented across various museum collections. One specimen in particular shows evidence of active primary feather moulting , which

464-572: A "thumb-like" form of leading edge slot , may indicate that Microraptor was capable of true, powered flight. Other studies have demonstrated that the wings of Microraptor were large enough to generate the lift necessary for powered launching into flight even without a fully vertical flight stroke. A 2016 study of incipient flight ability in paravians demonstrated that Microraptor was capable of wing-assisted incline running , as well as wing-assisted leaping and even ground-based launching. Stephen Czerkas, Gregory S. Paul, and others have argued that

580-543: A 2024 paper which reported the smallest known juvenile specimen of Microraptor , Wang and Pei included microraptorians and eudromaeosaurians within a new clade Serraraptoria. Microraptor had four wings , one on each of its forelimbs and hindlimbs, somewhat resembling one possible arrangement of the quartet of flight surfaces on a tandem wing aircraft of today. It had long pennaceous feathers on arms and hands 10–20 cm long (3.9–7.9 in) with legs and feet 11–15 cm long (4.3–5.9 in). The long feathers on

696-561: A Mesozoic mammal, the only other being a specimen of the compsognathid Sinosauropteryx . In the December 6, 2011 issue of Proceedings of the National Academy of Sciences , Jingmai O'Connor and coauthors described a specimen of Microraptor gui containing bones of an arboreal enantiornithean bird in its abdomen, specifically a partial wing and feet. Their position implies the bird was swallowed whole and head-first, which

812-668: A conventional interpretation and a tetrapteryx stage are equally possible. However, based on the presence of unusually long leg feathers in various feathered dinosaurs, Archaeopteryx , and some modern birds such as raptors, as well as the discovery of further dinosaurs with long primary feathers on their feet (such as Pedopenna ), the authors argued that the current body of evidence, both from morphology and phylogeny, suggests that bird flight did shift at some point from shared limb dominance to front-limb dominance and that all modern birds may have evolved from four-winged ancestors, or at least ancestors with unusually long leg feathers relative to

928-472: A deep U-shaped curve and then lifted again to land on another tree. The feathers not directly employed in the biplane wing structure, like those on the tibia and the tail , could have been used to control drag and alter the flight path , trajectory , etc. The orientation of the hindwings would also have helped the animal control its gliding flight. Chatterjee also used computer algorithms that test animal flight capacity to test whether or not Microraptor

1044-462: A diamond-shaped fan on the end of the tail (possibly for added stability during flight). Xu et al. (2003) compared the longer plumes on Microraptor ' s head to those of the Philippine eagle . Bands of dark and light present on some specimens may indicate color patterns present in life, though at least some individuals almost certainly possessed an iridescent black coloration. A diagnosis

1160-420: A distinct species with the specimen reported in 2013 being distinguishable from the type specimen of M. zhaoianus . A new specimen of Microraptor , BMNHC PH881, showed several features previously unknown in the animal, including the probably glossy-black iridescent plumage coloration. The new specimen also featured a bifurcated tailfan, similar in shape to previously known Microraptor tailfans except sporting

1276-442: A few teeth in the middle of the upper jaw (maxilla) but none in the front (premaxilla). The upper teeth of J. palmapenis seem to have been angled slightly forward as in some other basal avialans. The teeth in all three species were small, blunt and peg-like with no serrations. Their arms were robust and longer than the legs, with relatively well-developed shoulder girdles indicating strong wing musculature. The wishbone ( furcula )

SECTION 10

#1732791835603

1392-407: A genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

1508-522: A high-lift coefficient at the expense of high drag was likely the most efficient strategy for Microraptor when gliding between low elevations. Microraptor did not require a sophisticated, 'modern' wing morphology to be an effective glider. However, the idea that Microraptor was an arboreal glider relies on it to have regularly climbed or even lived in trees, when study of its anatomy have shown that its limb proportions fall in line with modern ground birds rather than climbers, and its skeleton shows none of

1624-651: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

1740-628: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

1856-901: A modern starling , and indicated iridescence in the plumage of Microraptor . Though the researchers state that the true function of the iridescence is yet unknown, it has been suggested that the tiny dromaeosaur was using its glossy coat as a form of communication or sexual display, much as in modern iridescent birds. The cladogram below follows a 2012 analysis by paleontologists Phil Senter, James I. Kirkland, Donald D. DeBlieux, Scott Madsen and Natalie Toth. Xiaotingia [REDACTED] Unenlagiinae [REDACTED] Shanag [REDACTED] Saurornitholestinae Velociraptorinae [REDACTED] Dromaeosaurinae [REDACTED] Tianyuraptor Hesperonychus Microraptor sp. Microraptor gui [REDACTED] Microraptor zhaoianus Cryptovolans Graciliraptor [REDACTED] Sinornithosaurus [REDACTED] In

1972-531: A pair of long, narrow feathers at the center of the fan. The new specimen also showed no sign of the nuchal crest, indicating that the crest inferred from the holotype specimen may be an artifact of taphonomic distortion. Numerous further specimens likely belonging to Microraptor have been uncovered, all from the Shangheshou Bed of the Jiufotang Formation in Liaoning, China. In fact, Microraptor

2088-421: A prerequisite for the flapping flight stroke in birds. Studies of maniraptoran anatomy have suggested that the shoulder socket did not shift into the bird-like position of a high, upward orientation close to the vertebral column until relatively advanced avialans like the enantiornithes appeared. However, other scientists have argued that the shoulder girdle in some paravian theropods, including Microraptor ,

2204-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

2320-424: A review by Phil Senter and colleagues in 2004, the scientists suggested that all these features represented individual variation across various age groups of a single Microraptor species, making the name Cryptovolans pauli and Microraptor gui junior synonyms of Microraptor zhaoianus . Many other researchers, including Alan Feduccia and Tom Holtz, have since supported its synonymy. M. gui has been accepted as

2436-635: A short, robust hand. However, like other basal (non-ornithothoracean) avialans and theropod dinosaurs, the shoulder blades of Jeholornis were oriented along the sides of the body, rather than on top of its back. This meant that the shoulder girdle was slung low, and according to a 2006 study by Phil Senter, would have allowed only for a typical dinosaurian motion of the shoulder. Primitive avialans like Archaeopteryx , Confuciusornis , and Jeholornis would not have been able to lift their arms vertically to achieve true flapping flight, though semi-powered gliding or parachuting would have been possible. Examination of

SECTION 20

#1732791835603

2552-488: A specialist for hunting in either habitats. In 2019, a new genus of scleroglossan lizard ( Indrasaurus ) was described from a specimen found in the stomach of a Microraptor . The Microraptor apparently swallowed its prey head first, a behavior typical of modern carnivorous birds and lizards. The Indrasaurus bones lacked marked pitting and scarring, indicating that the Microraptor died shortly after eating

2668-443: A subset of Avialae , the explicit definition of the term "bird" that Norell employs, would definitely exclude BPM 1 3-13. However, he does not consider the specimen to belong to Avialae either. Czerkas's interpretation of the hindleg feathers noted by Norell proved to be incorrect the following year when additional specimens of Microraptor were published by Xu and colleagues, showing a distinctive "hindwing" completely separate from

2784-418: A synonym of Microraptor . Like Archaeopteryx , well-preserved fossils of Microraptor provide important evidence about the evolutionary relationship between birds and earlier dinosaurs. Microraptor had long pennaceous feathers that formed aerodynamic surfaces on the arms and tail but also on the legs. This led paleontologist Xu Xing in 2003 to describe the first specimen to preserve this feature as

2900-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

3016-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

3132-549: Is a statement of the anatomical features of an organism (or group) that collectively distinguish it from all other organisms. Some, but not all, of the features in a diagnosis are also autapomorphies. An autapomorphy is a distinctive anatomical feature that is unique to a given organism. Several anatomical features found in Microraptor , such as a combination of unserrated and partially serrated teeth with constricted 'waists', and unusually long upper arm bones, are shared with both primitive avians and primitive troodontids . Microraptor

3248-403: Is curved in such a way that the shoulder joint could only have been positioned high on the back, allowing for a nearly vertical upstroke of the wing. This possibly advanced shoulder anatomy, combined with the presence of a propatagium linking the wrist to the shoulder (which fills the space in front of the flexed wing and may support the wing against drag in modern birds) and an alula , much like

3364-534: Is derived from "Shenzhou", an ancient name for China, and "raptor", Latin for "violent plunderer") was described in the July 2002 issue of Geological Bulletin of China by Ji et al., the same month as Jeholornis was described by Zhou and Zhang. Two of the diagnostic characteristics which could have distinguished Shenzhouraptor from Jeholornis were its smaller size and the absence of teeth, which may be attributed to age and preservational bias. The other major difference

3480-544: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

3596-622: Is in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. It is cataloged as IVPP V13274, and was reported in the journal Nature in 2002. A second specimen is in the collection of the Liaoning Provincial Museum of Paleontology, and is catalogued as LPM 0193 it was reported as a new species, Shenzhouraptor sinensis , in the journal The Geological Bulletin of China in 2002, but

Jeholornis - Misplaced Pages Continue

3712-522: Is likely a junior synonym of Jeholornis prima . Two more specimens were later accessioned by the IVPP as V13550 and V13553 and they were reported in the journal Naturwissenschaften in 2003. A fifth specimen, SDM 20090109, was described in 2012 and made the type specimen of the species J. palmapenis . A sixth specimen, STM2-51, was reported in 2013 and preserved round structures in the body cavity which were interpreted as ovaries. A seventh specimen, YFGP-yb2,

3828-518: Is one of the few known fossil evidence of such behavior among pennaraptoran dinosaurs. The initial naming of Microraptor was controversial, because of the unusual circumstances of its first description. The first specimen to be described was part of a chimeric specimen—a patchwork of different feathered dinosaur species ( Microraptor itself, Yanornis and an as-of-yet undescribed third species) assembled from multiple specimens in China and smuggled to

3944-432: Is particularly similar to the basal troodontid Sinovenator ; in their 2002 description of two M. zhaoianus specimens, Hwang et al. note that this is not particularly surprising, given that both Microraptor and Sinovenator are very primitive members of two closely related groups, and both are close to the deinonychosaurian split between dromaeosaurids and troodontids. In March 2012, Quanguo Li et al. determined

4060-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

4176-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

4292-501: Is the most abundant non-avialan dinosaur fossil type found in this formation. In 2010, it was reported that there were over 300 undescribed specimens attributable to Microraptor or its close relatives among the collections of several Chinese museums, though many had been altered or composited by private fossil collectors. Norell et al. (2002) described BPM 1 3-13 as the first dinosaur known to have flight feathers on its legs as well as on its arms. Czerkas (2002) mistakenly described

4408-475: Is uncertain what exact lineage of plant they represent. This J. prima specimen, while about two times heavier than the type specimen Shenzhouraptor , had three small teeth in the lower jaw, whereas no teeth were visible in the latter. Two other specimens, IVPP V13353 and the aforementioned V13550 are smaller still and most certainly immature individuals; they both have teeth. In the Shenzhouraptor type,

4524-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

4640-824: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

4756-646: The Jiufotang Formation , dating from the early Albian and now belong to the collection of the Paleontology Museum of Beipiao, in Liaoning , China. They are referred to by the inventory numbers LPM 0200, the holotype ; LPM 0201, its counterslab (slab and counterslab together represent the earlier BPM 1 3-13); and the paratype LPM 0159, a smaller skeleton. Both individuals are preserved as articulated compression fossils; they are reasonably complete but partially damaged. Czerkas et al. (2002) diagnosed

Jeholornis - Misplaced Pages Continue

4872-520: The dentary and anterior skull are poorly preserved and this makes it impossible to say whether there were any teeth. The jaw is deep, the dentaries are well fused, and the teeth are reduced, and all indicate a specialized seed-feeding habit for Jeholornis . In 2017 it was announced, that one specimen was fossilized with gastroliths in its stomach. A 2022 study by the University of Oxford , england and Linyi University showed that Jeholornis prima

4988-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

5104-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

5220-648: The USA for sale . After the forgery was revealed by Xu Xing of Beijing 's Institute of Vertebrate Paleontology and Paleoanthropology , Storrs L. Olson , curator of birds in the National Museum of Natural History of the Smithsonian Institution , published a description of the Microraptor's tail in an obscure journal, giving it the name Archaeoraptor liaoningensis in an attempt to remove

5336-414: The anatomical features expected of a flying animal, though it would have been a less advanced form of flight compared to birds. For example, some studies suggest the shoulder joint was too primitive to allow a full flapping flight stroke. In the ancestral anatomy of theropod dinosaurs, the shoulder socket faced downward and slightly backward, making it impossible for the animals to raise their arms vertically,

5452-684: The ancestral dromaeosaur could not glide or fly, but that there was good evidence that it was small-bodied (around 65 cm long and 600–700 g in mass). Microraptor was among the smallest-known non-avian dinosaurs , with the holotype of M. gui measuring 77 centimetres (2.53 ft) in length, 88–94 centimetres (2.89–3.08 ft) in wingspan and weighing 0.5–1.4 kilograms (1.1–3.1 lb). There are larger specimens which would have measured at least 80 centimetres (2.6 ft) in length, more than 99 centimetres (3.25 ft) in wingspan and weighed 1.25–1.88 kilograms (2.8–4.1 lb). Aside from their extremely small size, Microraptor were among

5568-446: The ankle ( metatarsus ). Zhonghe Zhou and Fucheng Zhang classified Jeholornis in a new family, Jeholornithidae , of which it is the type genus , and the order Jeholornithiformes . No phylogenetic 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

5684-622: The article describing Jeholornis was July 25, 2002. The discovery of Shenzhouraptor was reported in at least one newspaper on July 23, 2002, though the official paper naming the species, published in a monthly journal, did not bear a specific date of issue. In 2003, Ji and colleagues made Jeholornis a junior synonym of Shenzhouraptor . In 2006, Zhou and Zhang noted that the ICZN gives priority to these over monthly journals, and argued that because of this Jeholornis has priority over Shenzhouraptor . Most studies have since treated Jeholornis prima as

5800-437: The authors interpreted as implying that the Microraptor had caught and consumed the bird in the trees, rather than scavenging it. In 2013 researchers announced that they had found fish scales in the abdominal cavity of another M. gui specimen. The authors contradicted the prior suggestion that M. gui hunted only in an arboreal environment, proposing that it was also an adept hunter of fish as well. They further argued that

5916-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

SECTION 50

#1732791835603

6032-476: The body of the tail, so that the entire array of tail feathers resembled a palm frond. The tail feathers did not overlap, and so could not have formed a lift-generating surface, so the tail was probably used mainly for display. Jeholornis contains at least three species : the type species , Jeholornis prima (named in reference to the Jehol group of fossil beds where it was found, and the primitive appearance of

6148-486: The claw curvature in Jeholornis suggests it may have been able to perch and may have been at least partly arboreal , spending much of its time in trees. One key adaptation of modern perching birds is the reversed, opposable first toe, or "hallux." Jeholornis was initially described as having a reversed hallux, though others cast doubt on this interpretation, noting that the reversed appearance could be an artifact of

6264-404: The construction of a lightweight three-dimensional physical model used to perform glide tests. Using several hindleg configurations for the model, they found that the biplane model, while not unreasonable, was structurally deficient and needed a heavy-headed weight distribution for stable gliding, which they deemed unlikely. The study indicated that a laterally abducted hindwing structure represented

6380-551: The differences appeared to correspond with size, and likely age differences. Two further specimens, classified as M. zhaoianus in 2002 ( M. gui had not yet been named), have also been described by Hwang and colleagues. Czerkas also believed that the animal may have been able to fly better than Archaeopteryx , the animal usually referred to as the earliest known bird. He cited the fused sternum and asymmetrical feathers, and argued that Microraptor has modern bird features that make it more derived than Archaeopteryx . Czerkas cited

6496-409: The early Cretaceous Jiufotang Formation ( Aptian stage), 125 to 120 million years ago. Three species have been named ( M. zhaoianus , M. gui , and M. hanqingi ), though further study has suggested that all of them represent variation in a single species, which is properly called M. zhaoianus . Cryptovolans , initially described as another four-winged dinosaur, is usually considered to be

6612-542: The expected adaptations in animals specialized for climbing trees. Describing specimens originally referenced as a distinctive species ( Cryptovolans pauli ), paleontologist Stephen Czerkas argued Microraptor may have been a powered flier, and indeed possibly a better flyer than Archaeopteryx . He noted that the Microraptor's fused sternum, asymmetrical feathers, and features of the shoulder girdle indicated that it could fly under its own power, rather than merely gliding. Today, most scientists agree that Microraptor had

6728-514: The extant birds". The results of a phylogenetic analysis of all valid jeholornithiform species considered by Wang and colleagues is shown below: Archaeopteryx lithographica Archaeopteryx albersdoerferi Alcmonavis Jixiangornis Jeholornis palmapenis Shenzhouraptor sinensis Kompsornis Jeholornis prima Jeholornis curvipes Pygostylia Over 100 specimens of Jeholornis have been found, though only seven have been formally described. The type specimen

6844-477: The extent of the hindwings onto most of the animal's foot, many scientists have suggested that Microraptor would have been awkward during normal ground movement or running. The front wing feathers would also have hindered Microraptor when on the ground, due to the limited range of motion in the wrist and the extreme length of the wing feathers. A 2010 study by Corwin Sullivan and colleagues showed that, even with

6960-555: The fact Microraptor could fly and yet is also very clearly a dromaeosaurid suggests that the Dromaeosauridae , including later and larger species such as Deinonychus , were secondarily flightless. The work of Xu and colleagues also suggested that the ancestors of dromaeosaurids were probably small, arboreal, and capable of gliding , although later discoveries of more primitive dromaeosaurids with short forelimbs unsuitable for gliding have cast doubt on this view. Work done on

7076-571: The fact that this possibly volant animal is also very clearly a dromaeosaurid to suggest that the Dromaeosauridae might actually be a basal bird group, and that later, larger, species such as Deinonychus were secondarily flightless (Czerkas, 2002). The current consensus is that there is not enough evidence to conclude whether dromaeosaurs descended from an ancestor with some aerodynamic abilities. The work of Xu et al. (2003) suggested that basal dromaeosaurs were probably small, arboreal, and could glide. The work of Turner et al. (2007) suggested that

SECTION 60

#1732791835603

7192-474: The feather bases extended close to or in contact with the bones, as in modern birds, providing strong anchor points. It was originally thought that Microraptor was a glider , and probably lived mainly in trees, because the hindwings anchored to the feet of Microraptor would have hindered their ability to run on the ground. Some paleontologists have suggested that feathered dinosaurs used their wings to parachute from trees, possibly to attack or ambush prey on

7308-426: The first non- avialan dinosaurs discovered with the impressions of feathers and wings. Seven specimens of M. zhaoianus have been described in detail, from which most feather impressions are known. Unusual even among early birds and feathered dinosaurs, Microraptor is one of the few known bird precursors to sport long flight feathers on the legs as well as the wings. Their bodies had a thick covering of feathers, with

7424-522: The forelimb wing. The first of these specimens was discovered in 2001, and between 2001 and 2003 four more specimens were bought from private collectors by Xu's museum, the Institute of Vertebrate Paleontology and Paleoanthropology . Xu also considered these specimens, most of which had hindwings and proportional differences from the original Microraptor specimen, to be a new species, which he named Microraptor gui . However, Senter also questioned this classification, noting that as with Cryptovolans , most of

7540-438: The forewings and hindwings must have been on different levels (as on a biplane ) and not overlaid (as on a dragonfly ), and that the latter posture would have been anatomically impossible. Using this biplane model, Chatterjee was able to calculate possible methods of gliding and determined that Microraptor most likely employed a phugoid style of gliding: launching itself from a perch, the animal would have swooped downward in

7656-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

7772-412: The former became a nomen protectum and the latter a nomen oblitum due to revisions in the ICZN rules that took place on December 31, 1999. In addition, Xu's name for the type specimen ( Microraptor ) was subsequently used more frequently than the original name; as such, this and the chimeric nature of the specimen would render the name "Archaeoraptor" a nomen vanum (as it was improperly described) and

7888-686: The fossil as having no long feathers on its legs, but only on its hands and arms, as he illustrated on the cover of his book Feathered Dinosaurs and the Origin of Flight . In his discussion of Cryptovolans in this book, Czerkas strongly denounces Norell's conclusions; "The misinterpretation of the primary wing feathers as being from the hind legs stems directly to [ sic ] seeing what one believes and wants to see". Czerkas also denounced Norell for failing to conclude that dromaeosaurs are birds, accusing him of succumbing to "...the blinding influences of preconceived ideas." The crown group definition of Aves, as

8004-737: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

8120-424: The genus on the basis of having primary feathers (which in the authors' opinion made it a bird ), a co-ossified sternum, a tail consisting of 28 to 30 vertebrae and a third finger with a short phalanx III-3. Some of the feathers Czerkas described as primary were actually attached to the leg, rather than the arm. This, along with most of the other diagnostic characters, is also present in the genus Microraptor , which

8236-498: The ground, as a precursor to gliding or true flight. In their 2007 study, Chatterjee and Templin tested this hypothesis as well, and found that the combined wing surface of Microraptor was too narrow to successfully parachute to the ground without injury from any significant height. However, the authors did leave open the possibility that Microraptor could have parachuted short distances, as between closely spaced tree branches. Wind tunnel experiments have demonstrated that sustaining

8352-464: The hallux could appear reversed or not depending on the position the specimen was fossilized in, and that the toe bones showed intermediate adaptations between a reversed and non-reversed hallux. They concluded that the first toe of Jeholornis was generally held in reversed position, but had not yet acquired the advanced adaptations for reversal seen in more advanced perching birds. [REDACTED] [REDACTED] Genus The composition of

8468-492: The junior synonym Microraptor a nomen protectum (as it's been used in more published works than "Archaeoraptor" and was properly described). The first specimen referred to Microraptor represented a small individual and included faint feather remnants, but was otherwise not well preserved and lacked a skull. In 2002 Mark Norell et al. described another specimen, BPM 1 3-13, which they did not name or refer to an existing species. Later that year Stephen Czerkas et al. named

8584-633: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

8700-521: The legs of Microraptor were true flight feathers as seen in modern birds , with asymmetrical vanes on the arm, leg, and tail feathers. As in modern bird wings, Microraptor had both primary (anchored to the hand) and secondary (anchored to the arm) flight feathers. This standard wing pattern was mirrored on the hindlegs, with flight feathers anchored to the upper foot bones as well as the upper and lower leg. Though not apparent in most fossils under natural light, due to obstruction from decayed soft tissue,

8816-451: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Microraptor Microraptor ( Greek , μικρός, mīkros : "small"; Latin , raptor : "one who seizes") is a genus of small, four-winged dromaeosaurid dinosaurs . Numerous well-preserved fossil specimens have been recovered from Liaoning , China . They date from

8932-512: The model used by Alexander and his team, noting that the hip anatomy was not consistent with other dromaeosaurs. In most dromaeosaurids, features of the hip bone prevent the legs from splaying horizontally; instead, they are locked in a vertical position below the body. Alexander's team used a specimen of Microraptor which was crushed flat to make their model, which Brougham and Brusatte argued did not reflect its actual anatomy. Later in 2010, Alexander's team responded to these criticisms, noting that

9048-418: The modern configuration. In 2010 researchers announced that further preparation of the type fossil of M. zhaoianus revealed preserved probable gut contents, and a full study on them was later published in 2022 by David Hone and colleagues. These consisted of the remains of a mammal, primarily a complete and articulated right foot (including all tarsals , metatarsals , and most of the phalanges ) as well as

9164-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

9280-405: The most biologically and aerodynamically consistent configuration for Microraptor . A further analysis by Brougham and Brusatte, however, concluded that Alexander's model reconstruction was not consistent with all of the available data on Microraptor and argued that the study was insufficient for determining a likely flight pattern for Microraptor . Brougham and Brusatte criticized the anatomy of

9396-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

9512-401: The name from the paleornithological record by assigning it to the part least likely to be a bird. However, Xu had discovered the remains of the specimen from which the tail had been taken and published a description of it later that year, giving it the name Microraptor zhaoianus . Since the two names designate the same individual as the type specimen, Microraptor zhaoianus would have been

9628-976: The older Yixian Formation . Jeholornis had long tails and few small teeth , and were approximately the size of turkeys , making them among the largest avialans known until the Late Cretaceous. Their diet included seeds of cycads , Ginkgo or similar plants . Jeholornis were relatively large, basal avialans, with a maximum adult length of up to 75 cm (2.5 ft) and an estimated weight of 2.27-9.1 kg (5-20 lbs). Another estimation listed it at 85 cm (2.6 ft) and 780 gr (1.72 lbs). Their skulls were short and high, similar to basal paravians like Epidexipteryx and to early oviraptorosaurs like Incisivosaurus . The lower jaws were short, stout, and curved downward, possibly an adaptation for eating seeds. Jeholornis prima lacked teeth in their upper jaws, and had only three small teeth in their lower jaws, while J. palmapenis had

9744-471: The plant spread and grow into more fruit producing plants providing more food scorces for Jeholornis . The shoulder girdles of Jeholornis were well developed and probably allowed for better flight capability than seen in Archaeopteryx . The flight apparatus of the Jeholornis was overall quite similar to that of Confuciusornis in form and function, with forelimbs longer than hindlimbs, and

9860-545: The plumage coloration of Microraptor based on the new specimen BMNHC PH881, which also showed several other features previously unknown in Microraptor . By analyzing the fossilized melanosomes (pigment cells) in the fossil with scanning electron microscope techniques, the researchers compared their arrangements to those of modern birds. In Microraptor , these cells were shaped in a manner consistent with black, glossy coloration in modern birds. These rod-shaped, narrow melanosomes were arranged in stacked layers, much like those of

9976-527: The preservation is too poor. The tails of several specimens preserve a fan of feathers ( rectrices ) at the tip, shorter than those on the forelimbs. The feather fan is similar to those of Microraptor and Caudipteryx , being restricted to the tip of the tail, unlike those of Archaeopteryx and Similicaudipteryx which have rectrices extending down much of the tail length. In at least one species, Jeholornis palmapenis , there were 11 tail feathers. The feathers were short and pointed, and arched away from

10092-541: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

10208-703: The question of flight ability in other paravians, however, showed that most of them probably would not have been able to achieve enough lift for powered flight, given their limited flight strokes and relatively smaller wings. These studies concluded that Microraptor probably evolved flight and its associated features (fused sternum, alula, etc.) independently of the ancestors of birds. In 2024, Kiat and O'Connor analyzed that Mesozoic birds and Microraptor had remex morphologies that are consistent with modern volant birds, while anchiornithids and Caudipteryx were secondarily flightless. Sankar Chatterjee suggested in 2005 that, in order for Microraptor to glide or fly,

10324-451: The question of whether the evolution of flight in modern birds went through a four-winged stage, or whether four-winged gliders like Microraptor were an evolutionary side-branch that left no descendants. As early as 1915, naturalist William Beebe had argued that the evolution of bird flight may have gone through a four-winged (or tetrapteryx ) stage. Chatterjee and Templin did not take a strong stance on this possibility, noting that both

10440-440: The related dromaeosaur Hesperonychus , which is known from complete hip bones preserved in three dimensions, also shows hip sockets directed partially upward, possibly allowing the legs to splay more than in other dromaeosaurs. However, Hartman and colleagues suggested that Hesperonychus is not a dromaeosaur, but actually an avialan close to modern birds like Balaur bondoc based on phylogenetic analyses in 2019. Due to

10556-405: The reliability of these interpretations and wrote that both could just as equally be attributed to scavenging. Further, they argued against Microraptor being a specialist in either or both arboreal or aquatic hunting, citing the broad range of vertebrate gut contents (i.e. fish, mammals, lizards, birds) as evidence for a generalist hunting strategy, and that neither required that Microraptor being

10672-470: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

10788-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

10904-479: The shafts of additional long bones and potentially other fragments. The foot skeleton is similar to those of Eomaia and Sinodelphys . It corresponds to an animal with an estimated snout to vent length of 80 mm (3.1 in) and a mass of 13–43 g (0.46–1.52 oz). The unguals of the foot are less curved than in Eomaia or Sinodelphys , indicating that the mammal could climb but less effectively than in

11020-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

11136-430: The specimen Cryptovolans pauli , and referred two additional specimens (the first to show well-preserved feathers) to this species. The generic name was derived from Greek kryptos , "hidden", and Latin volans , "flying". The specific name , pauli , honors paleontologist Gregory S. Paul , who had long proposed that dromaeosaurids evolved from flying ancestors. The type specimens of C. pauli were collected from

11252-453: The specimen showed a probable adaptation to a fish-eating diet, pointing to the first three teeth of the mandible being inclined anterodorsally, a characteristic often associated with piscivory. They concluded that Microraptor was an opportunistic feeder, hunting the most common prey in both arboreal and aquatic habitats. Both of these studies regarded each gut contents as instances of predation. However, Hone and colleagues (2022) questioned

11368-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

11484-421: The suggestion that they are synonymous. A phylogenetic analysis supported this conclusion, recovering Shenzhouraptor as a less derived species outside of a clade composed of Jeholornis prima , J. curvipes and Kompsornis . The type fossil of Jeholornis prima preserved over 50 round seeds in the area of the crop , each about 8-10 millimeters wide. The seeds belong to the form genus Carpolithes , thus it

11600-406: The tail) and two referred species, Jeholornis palmapenis described by Jingmai O'Connor and colleagues in 2012, and Jeholornis curvipes , described by Ulysse Lefèvre and colleagues in 2014. The name J. palmapenis translates to "palm tail" in reference to the unusual arrangement of its tail feathers, while the name J. curvipes means "curved foot" due to a distinctive bend in the bones just above

11716-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

11832-429: The two latter genera and so was likely not arboreal but potentially scansorial. It is ambiguous whether the mammal had been predated upon or scavenged by the Microraptor , although the lack of other definitive body parts consumed may suggest the low-muscle mass foot may have been eaten during a late stage of carcass consumption, possibly through scavenging. The find is a rare example of a theropod definitively consuming

11948-439: The type specimen of J. palmapenis . A study by Gregory M. Erickson in 2009 has shown that Jeholornis (along with Archaeopteryx ) had relatively slow ontogenic development, i.e. they grew very slowly, compared to most modern birds, which grow very quickly. The living kiwi birds however, have slow development, and it has been speculated that Jeholornis could have had a metabolism similar to these. Feather traces from

12064-428: The valid name for the species. In 2020, a publication of a new genus and species of jeholornithiform, Kompsornis longicaudus , by Wang and colleagues included a re-evaluation of the diagnostic characteristics of all Jeholornis species, including the holotype of Shenzhouraptor . This examination concluded that Shenzhouraptor was a valid species distinct from Jeholornis prima and other jeholornithiforms, rejecting

12180-576: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

12296-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

12412-502: The way the fossils were crushed. Indeed, in most avialans with a reversed hallux, the foot bone where the reversed toe attaches is twisted, allowing the toe to point backward, but this feature is not found in any Jeholornis specimen. In a 2008 presentation for the conference of the Society of Avian Paleontology and Evolution (SAPE), Zhiheng Li and Yuguang Zhang re-examined the evidence for a reversed hallux in Jeholornis . They found that

12528-528: The wing folded as far as possible, the feathers would still have dragged along the ground if the arms were held in a neutral position, or extended forward as in a predatory strike. Only by keeping the wings elevated, or the upper arm extended fully backward, could Microraptor have avoided damaging the wing feathers. Therefore, it may have been anatomically impossible for Microraptor to have used its clawed forelimbs in capturing prey or manipulating objects. The unique wing arrangement found in Microraptor raised

12644-403: The wing have only been identified in two specimens, LPM 0193 ( J. prima ) and (SDM 20090109.1 ( J. palmapenis ). The first specimen shows that the flight feathers were asymmetrical (and therefore aerodynamic, as in modern flying birds) and up to 21 centimeters long, longer than the forearm and hand combined. The exact number of flight feathers cannot be determined from known specimens, however, as

12760-506: Was U-shaped in J. prima and J. palmapenis but not in J. curvipes . Their fingers were short compared to those of Archaeopteryx and also more robust. The lower legs were not particularly long, indicating that these animals were not specialized runners. The first toe, or hallux , which is reversed in modern birds and used to perch in trees, was only partially reversed in both Jeholornis species, pointing inward and slightly backward. The halluces of Jeholornis were short, but their claw

12876-436: Was a different number of caudal vertebrae , though Zhou and Zhang showed in 2003 that the specimen was missing several of the proximal caudals. Several scientists have come to the conclusion that Jeholornis and Shenzhouraptor are specimens of the same species. However, both names were published in print within days of each other, and there was initially controversy over which name should be considered official. The date on

12992-412: Was capable of true, powered flight, as opposed to or in addition to passive gliding. The resulting data showed that Microraptor did have the requirements to sustain level powered flight, so it is theoretically possible that the animal flew, as opposed to gliding. Some paleontologists have doubted the biplane hypothesis, and have proposed other configurations. A 2010 study by Alexander et al. described

13108-411: Was described in 2014 and made the type specimen of a third species, J. curvipes . The non-pygostylian avialan Jixiangornis orientalis was considered a possible synonym of Jeholornis prima . However, a phylogenetic analysis performed in 2014 found that it may actually be more closely related to short-tailed avialans ( Pygostylia ) than to Jeholornis . Shenzhouraptor sinensis (the name of which

13224-413: Was first described earlier than Cryptovolans . However, BPM 1 3-13 has a longer tail, proportionately, than other Microraptor specimens that had been described by 2002, which have 24 to 26 tail vertebrae. Subsequent studies (and more specimens of Microraptor ) have shown that the features used to distinguish Cryptovolans are not unique, but are present to varying degrees across various specimens. In

13340-513: Was more strongly curved than those of the other toes. Unlike deinonychosaurs and some other Mesozoic avialans, the claw of the second toe was not enlarged relative to the other claws. Their tail anatomy was more like those of dromaeosaurids than Archaeopteryx , with more strongly interlocking vertebrae, and though they had a similar number of tail vertebrae (between 20 and 24) those of Jeholornis were much longer overall than those of Archaeopteryx . The only well-preserved tail feathers come from

13456-466: Was the earliest known fruit eating bird. This trait possibly developed when plants somewhere around 135 million years ago started developing new kinds of fruits. Some birds like Jeholornis evolved the ability to eat the fruits and a co-evolutionary relationship started about 120 million years ago. During this study, they also found that Jeholornis was not just eating the seeds but the entire fruit itself. It would have defecated un-crushed seeds helping

#602397