Velociraptor
Velociraptor | |
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Mounted V. mongoliensis cast at Royal Belgian Institute of Natural Sciences
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | †Dromaeosauridae |
Clade: | †Eudromaeosauria |
Subfamily: | †Velociraptorinae |
Genus: | †Velociraptor Osborn, 1924 |
Type species | |
†Velociraptor mongoliensis Osborn, 1924
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Other species | |
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Velociraptor (
Smaller than other dromaeosaurids like , with an upturned snout.
Velociraptor (commonly referred to as "raptor") is one of the dinosaur genera most familiar to the general public due to its prominent role in the Jurassic Park films. In reality, however, Velociraptor was roughly the size of a turkey, considerably smaller than the approximately 2 m (6.6 ft) tall and 90 kg (200 lb) reptiles seen in the novels and films (which were based on members of the related genus Deinonychus). Today, Velociraptor is well known to paleontologists, with over a dozen described fossil skeletons. One particularly famous specimen preserves a Velociraptor locked in combat with a Protoceratops.
History of discovery
During an
While North American teams were shut out of communist Mongolia during the Cold War, expeditions by Soviet and Polish scientists, in collaboration with Mongolian colleagues, recovered several more specimens of Velociraptor. The most famous is part of the "Fighting Dinosaurs" specimen (MPC-D 100/25; formerly IGM, GIN, or GI SPS), discovered by a Polish-Mongolian team in 1971. The fossil preserves a Velociraptor in battle against a Protoceratops.[4][5][6] It is considered a national treasure of Mongolia, and in 2000 it was loaned to the American Museum of Natural History in New York City for a temporary exhibition.[7]
Between 1988 and 1990, a joint Chinese-Canadian team discovered Velociraptor remains in northern China.[8] American scientists returned to Mongolia in 1990, and a joint Mongolian-American expedition to the Gobi, led by the American Museum of Natural History and the Mongolian Academy of Sciences, turned up several well-preserved skeletons.[9][10] One such specimen, MPC-D 100/980, was nicknamed "Ichabodcraniosaurus" by Norell's team because the fairly complete specimen was found without its skull (an allusion to the Washington Irving character Ichabod Crane).[11] While Norell and Makovicky provisionally considered it a specimen of Velociraptor mongoliensis,[9] it was named as a new species Shri devi in 2021.[12]
In 1999, Rinchen Barsbold and Halszka Osmólska reported a juvenile Velociraptor specimen (GIN or IGM 100/2000), represented by a complete skeleton including the skull of a young individual. It was found at the Tugriken Shireh locality of the Djadochta Formation during the context of the Mongolian-Japanese Palaeontological Expeditions. The coauthors stated that detailed descriptions of this and other specimens would be published at a later date.[13]
Additional species
Maxillae and a lacrimal (the main tooth-bearing bones of the upper jaw, and the bone that forms the anterior margin of the eye socket, respectively) recovered from the Bayan Mandahu Formation in 1999 by the Sino-Belgian Dinosaur Expeditions were found to pertain to Velociraptor, but not to the type species V. mongoliensis. Pascal Godefroit and colleagues named these bones V. osmolskae (for Polish paleontologist Halszka Osmólska) in 2008.[14] However, the 2013 study noted that while "the elongate shape of the maxilla in V. osmolskae is similar to that of V. mongoliensis," phylogenetic analysis found it to be closer to Linheraptor, making the genus paraphyletic; thus, V. osmolskae might not actually belong to the genus Velociraptor and requires reassessment.[15]
Paleontologists Mark A. Norell and Peter J. Makovicky in 1997 described new and well preserved specimens of V. mongoliensis, namely MPC-D 100/985 collected from the Tugrik Shireh locality in 1993, and MPC-D 100/986 collected in 1993 from the Chimney Buttes locality. The team briefly mentioned another specimen, MPC-D 100/982, which by the time of this publication remained undescribed.[10] In 1999 Norell and Makovicky provided more insights into the anatomy of Velociraptor with additional specimens. Among these, MPC-D 100/982 was partially described and figured, and referred to V. mongoliensis mainly based on cranial similarities with the holotype skull, although they stated that differences were present between the pelvic region of this specimen and other Velociraptor specimens. This relatively well-preserved specimen including the skull was discovered and collected in 1995 at the Bayn Dzak locality (specifically at the "Volcano" sub-locality).[9] Martin Kundrát in a 2004 abstract compared the neurocranium of MPC-D 100/982 to another Velociraptor specimen, MPC-D 100/976. He concluded that the overall morphology of the former was more derived (advanced) than the latter, suggesting that they could represent distinct taxa.[16]
Mark J. Powers in his 2020 master thesis fully described MPC-D 100/982, which he concluded to represent a new and third species of Velociraptor. This species, which he considered distinct, was stated to mainly differ from other Velociraptor species in having a shallow maxilla morphology.
Description
Velociraptor was a small to medium-sized
Prominent
Skull
The skull of Velociraptor was rather elongated and grew up to 23 cm (9.1 in) long. It was uniquely up-curved at the snout region, concave on the upper surface, and convex on the lower surface. The snout, which occupied about 60% of the entire skull length, was notably narrow and mainly formed by the nasal, premaxilla, and maxilla bones. The premaxilla was the anteriormost bone in the skull, and it was longer than taller. While its posterior end joined the nasal, the main body of the premaxilla touched the maxilla. The maxilla was nearly triangular in shape and the largest element of the snout. On its center or main body, there was a depression developing a small oval to circular-shaped hole, called maxillary fenestra. Though in front of this fenestra were two small openings, referred to as promaxillary fenestrae. The posterior border of the maxilla formed (predominantly) the antorbital fenestra, one of the several large holes in the skull. Both premaxilla and maxilla had several alveoli (tooth sockets) on their bottom surfaces. Above the maxilla and making contact with the premaxilla, there was the nasal bone. It was a thin/narrow and elongated bone contributing to the top surface of the snout. Together, both premaxilla and nasal bones gave form to the naris or narial fenestra (nostril opening), which was relatively large and circular. The posterior end of the nasal was joined by the frontal and lacrimal bones.[30][13]
The back or anterior region of the skull was built by the frontal, lacrimal, postorbital, jugal, parietal, quadrate, and quadratojugal bones. The
The lower jaw of Velociraptor comprised mainly the dentary, splenial, angular, surangular, and articular bones. The dentary was a very long, weakly curved, and narrow element that developed several alveoli on its top surface. On its posterior end, it meet the surangular. It had a small hole near its posterior end, called surangular foramen or fenestra. Both bones were the largest elements of the lower jaw of Velociraptor, contributing to virtually its entire length. Below them were the smaller splenial and angular, closely articulated to each other. The articular, located on the inner side of the surangular, was a small element that joined the quadrate of the upper skull, enabling the articulation with the lower jaw. An elongated, near oval-shaped hole was developed in the center of the lower jaw (the mandibular fenestra), and it was produced by the joint of the dentary, surangular, and angular bones.[30][13]
The teeth of Velociraptor were fairly
Postcranial skeleton
The arm of Velociraptor was formed by the
As in other dromaeosaurs, Velociraptor tails had
Classification
Velociraptor is a member of the group
When first described in 1924, Velociraptor was placed in the family Megalosauridae, as was the case with most carnivorous dinosaurs at the time (Megalosauridae, like Megalosaurus, functioned as a sort of 'wastebin' taxon, where many unrelated species were grouped together).[2] As dinosaur discoveries multiplied, Velociraptor was later recognized as a dromaeosaurid. All dromaeosaurids have also been referred to the family Archaeopterygidae by at least one author (which would, in effect, make Velociraptor a flightless bird).[36] In the past, other dromaeosaurid species, including Deinonychus antirrhopus and Saurornitholestes langstoni, have sometimes been classified in the genus Velociraptor. Since Velociraptor was the first to be named, these species were renamed Velociraptor antirrhopus and V. langstoni.[21] As of 2008,[update] the only currently recognized species of Velociraptor are V. mongoliensis[13][36][37] and V. osmolskae.[14] However, several studies have found "V." osmolskae to be distantly related to V. mongoliensis.[38][39]
Below are the results for the Eudromaeosauria
Paleobiology
Feathers
In 2007 Alan H. Turner and colleagues reported the presence of six
Because of the presence of another dromaeosaurid in Ukhaa Tolgod, Tsaagan, Napoli and team have noted that the referral of this specimen to Velociraptor is currently subject to reexamination.[26]
Senses
Examinations of the endocranium of Velociraptor indicate that it was able to detect and hear a wide range of sound frequencies (2,368–3,965 Hz) and could track prey with ease as a result. The endocranium examinations also further cemented the theory that the dromaeosaur was an agile, swift predator. Fossil evidence suggesting Velociraptor scavenged also indicates that it was an opportunistic and actively predatory animal, feeding on carrion during times of drought or famine, if in poor health, or depending on the animal's age.[40]
Feeding
In 2020, Powers and colleagues re-examined the
Manabu Sakamoto in 2022 performed a Bayesian phylogenetic predictive modelling framework for estimating jaw muscle parameters and bite forces of several extinct archosaurs, based on skull widths and phylogenetic relationships between groups. Among studied taxa, Velociraptor was scored with a bite force of 304 N, which was lower than that of other dromaeosaurids such as Dromaeosaurus (885 N) or Deinonychus (706 N).[42]
Predatory behavior
The "
The distinctive claw, on the second digit of dromaeosaurids, has traditionally been depicted as a slashing weapon; its assumed use being to cut and
Remains of Deinonychus, a closely related dromaeosaurid, have commonly been found in aggregations of several individuals. Deinonychus has also been found in association with the large ornithopod Tenontosaurus, which has been cited as evidence of cooperative (pack) hunting.[47][48] However, the only solid evidence for social behavior of any kind among dromaeosaurids comes from a Chinese trackway which shows six individuals of a large species moving as a group.[49] Although many isolated fossils of Velociraptor have been found in Mongolia, none were closely associated with other individuals.[37] Therefore, while Velociraptor is commonly depicted as a pack hunter, as in Jurassic Park, there is only limited fossil evidence to support this theory for dromaeosaurids in general and none specific to Velociraptor itself. Dromeosaur footprints in China suggest that a few other raptor genera may have hunted in packs, but there have been no conclusive examples of pack behavior found.[50][51]
In 2011, Denver Fowler and colleagues suggested a new method by which dromaeosaurs like Velociraptor and similar dromaeosaurs may have captured and restrained prey. This model, known as the "raptor prey restraint" (RPR) model of predation, proposes that dromaeosaurs killed their prey in a manner very similar to extant
Scavenging behavior
In 2010, Hone and colleagues published a paper on their 2008 discovery of shed teeth of what they believed to be a Velociraptor near a tooth-marked jaw bone of what they believed to be a Protoceratops in the Bayan Mandahu Formation. The authors concluded that the find represented "late-stage carcass consumption by Velociraptor" as the predator would have eaten other parts of a freshly killed Protoceratops before biting in the jaw area. The evidence was seen as supporting the inference from the "Fighting Dinosaurs" fossil that Protoceratops was part of the diet of Velociraptor.[52]
In 2012, Hone and colleagues published a paper that described a Velociraptor specimen with a long bone of an
In a 2024 study by Tse, Miller, and Pittman et al., focusing on the skull morphology and bite forces of various dromaeosaurids, it was discovered that Velociraptor had high bite force resistance compared to other dromaeosaurids such as Dromaeosaurus itself and Deinonychus, the latter of which was much larger. It is theorized by the authors that high bite force resistance was an adaptation towards obtaining food through scavenging more often than through active predation in Velociraptor. [54]
Metabolism
Velociraptor was warm-blooded to some degree, as it required a significant amount of energy to hunt. Modern animals that possess feathery or furry coats, like Velociraptor did, tend to be warm-blooded, since these coverings function as insulation. However, bone growth rates in dromaeosaurids and some early birds suggest a more moderate metabolism, compared with most modern warm-blooded mammals and birds. The kiwi is similar to dromaeosaurids in anatomy, feather type, bone structure and even the narrow anatomy of the nasal passages (usually a key indicator of metabolism). The kiwi is a highly active, if specialized, flightless bird, with a stable body temperature and a fairly low resting metabolic rate, making it a good model for the metabolism of primitive birds and dromaeosaurids.[36]
In 2023, Seishiro Tada and team examined the nasal cavities of
Paleopathology
Norell with colleagues in 1995 reported one V. mongoliensis skull bearing two parallel rows of small punctures on its frontal bones that, upon closer examination, match the spacing and size of Velociraptor teeth. They suggested that the wound was likely inflicted by another Velociraptor during a fight between the species. Because its bone structure shows no sign of healing near the bite wounds and the overall specimen was not scavenged, this individual was likely killed by this fatal wound.[56] In 2001 Molnar and team noted that this specimen is MPC-D 100/976 hailing from the Tugrik Shireh locality, which has also yielded the Fighting Dinosaurs specimen.[57]
In 2012 David Hone and team reported another injured Velociraptor specimen (MPC-D 100/54, roughly a sub-adult individual) found with the bones of an azhdarchid pterosaur within its stomach cavity, was carrying or recovering from an injury sustained to one broken rib. From evidence on the pterosaur bones, which were devoid of pitting or deformations from digestion, the Velociraptor died shortly after, possibly from the earlier injury. Nevertheless, the team noted that this broken ribs shows signs of bone healing.[53]
Paleoenvironment
Bayan Mandahu Formation
In both Bayan Mandahu and Djadochta formations many of the same genera were present, though they varied at the species level. These differences in species composition may be due a natural barrier separating the two formations, which are relatively close to each other geographically.[14] However, given the lack of any known barrier which would cause the specific faunal compositions found in these areas, it is more likely that those differences indicate a slight time difference.[58]
V. osmolskae lived alongside the ankylosaurid
Djadochta Formation
Known specimens of Velociraptor mongoliensis have been recovered from the
The Djadochta Formation is separated into a lower Bayn Dzak Member and upper Turgrugyin Member. V. mongoliensis is known from both members, represented by numerous specimens.
V. mongoliensis has been found at many of the most famous and prolific Djadochta localities. The type specimen was discovered at the Flaming Cliffs site (sublocality of the larger Bayn Dzak locality/region),[2] while the "Fighting Dinosaurs" were found at the Tugrik Shire locality (also known as Tugrugeen Shireh and many other spellings).[5] The latter is notorious for its exceptional in situ fossil preservation. Based on deposits (such as structureless sandstones), it has been concluded that a large number of specimens were buried alive during powerful sand-bearing events, common to these paleoenvironments.[65]
Cultural significance
Velociraptor is commonly perceived as a vicious and cunning killer thanks to their portrayal in the 1990 novel Jurassic Park by Michael Crichton and its 1993 film adaptation, directed by Steven Spielberg. The "raptors" portrayed in Jurassic Park were actually modeled after the closely related dromaeosaurid Deinonychus. Paleontologists in both the novel and film excavate a skeleton in Montana, far from the central Asian range of Velociraptor but characteristic of the Deinonychus range.[66] Crichton met with the discoverer of Deinonychus, John Ostrom, several times at Yale University to discuss details of the animal's possible range of behaviors and appearance. Crichton at one point apologetically told Ostrom that he had decided to use the name Velociraptor in place of Deinonychus because the former name was "more dramatic." According to Ostrom, Crichton stated that the Velociraptor of the novel was based on Deinonychus in almost every detail, and that only the name had been changed. The Jurassic Park filmmakers also requested all of Ostrom's published papers on Deinonychus during production.[67] They portrayed the animals with the size, proportions, and snout shape of Deinonychus rather than Velociraptor.[68][69]
Production on Jurassic Park began before the discovery of the large dromaeosaurid Utahraptor was made public in 1991, but as Jody Duncan wrote about this discovery: "Later, after we had designed and built the raptor, there was a discovery of a raptor skeleton in Utah, which they labeled 'super-slasher.' They had uncovered the largest Velociraptor to date and it measured five-and-a-half-feet tall, just like ours. So we designed it, we built it, and then they discovered it. That still boggles my mind."[68] Spielberg's name was briefly considered for naming of the new dinosaur in exchange for funding of field work, but no agreement was reached.[70]
Jurassic Park and its sequel The Lost World: Jurassic Park were released before the discovery that dromaeosaurs had feathers, so the Velociraptor in both films were depicted as scaled and featherless. For Jurassic Park III, the male Velociraptor was given quill-like structures along the back of the head and neck, but these structures do not resemble the feathers that Velociraptor would have had in reality due to reasons of continuity.[71] The Jurassic World sequel trilogy ignored the feathers of Velociraptor, adhering to the designs from Jurassic Park.[72] However, the dromaeosaur Pyroraptor was feathered for Jurassic World Dominion, along with other changes such as stiffening the tail to account for ossified tendons and de-pronating the hands.[73]
See also
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External links
- Media related to Velociraptor at Wikimedia Commons
- Data related to Velociraptor at Wikispecies
- Quotations related to Velociraptor at Wikiquote
- Wikijunior Dinosaurs/Velociraptor at Wikibooks
- 3D skull model of Velociraptor mongoliensis at Sketchfab
- Skeletal reconstruction of Velociraptor mongoliensis at Dr. Scott Hartman's Skeletal Drawing
- Videos about the Fighting Dinosaurs at American Museum of Natural History (Wayback Machine)