Bambiraptor Temporal range: Late Cretaceous, | |
---|---|
Restored skeleton of the juvenile specimen | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Dromaeosauridae |
Clade: | † Eudromaeosauria |
Subfamily: | † Saurornitholestinae |
Genus: | † Bambiraptor Burnham et al., 2000 |
Type species | |
†Bambiraptor feinbergi Burnham et al., 2000 |
Bambiraptor is a Late Cretaceous, 72-million-year-old, bird-like dromaeosaurid theropod dinosaur described by scientists at the University of Kansas, Yale University, and the University of New Orleans.
The holotype fossil is less than one meter long, although this specimen appears to be a juvenile, [1] and it is possible that Bambiraptor is a juvenile Saurornitholestes . [2] It is even suspected that the type specimen is a chimera, based on the fact that "there are elements of three different similarly sized lower legs included in the holotype." [2] Because of its small size, it was named Bambiraptor feinbergi, after the popular Disney movie character (the name literally translates to "Bambi thief") and the surname of the wealthy family who bought and lent the specimen to the new Graves Museum of Natural History in Florida.
The Bambiraptor skeleton was discovered in 1995 by 14-year-old fossil hunter Wes Linster, who was looking for dinosaur bones with his parents near Glacier National Park in Montana, United States. Linster told Time magazine that he uncovered the skeleton on a tall hill and was amazed at his discovery. "I bolted down the hill to get my mom because I knew I shouldn't be messing with it", he said. The bones that Linster discovered on that hilltop led to the excavation of a skeleton that was approximately 95 percent complete. Because of its completeness Florida Paleontology Institute Director Martin Shugar compared it to the Rosetta Stone that enabled archaeologists to translate Egyptian hieroglyphics. Yale paleontologist John Ostrom, who reintroduced the theory of bird evolution from dinosaurs after his 1964 discovery of Deinonychus in Wyoming, agreed, calling the specimen a "jewel", and telling reporters that the completeness and undistorted qualities of the bones should help scientists further understand the dinosaur-bird link.
The fossil first was seen as the young of Saurornitholestes and in 1997 reported as belonging to a Velociraptor sp. [3] In 2000 it was named and described by David Burnham, Kraig Derstler, Phil Currie, Robert Bakker, Zhou Zhonge and John Ostrom as a new genus: Bambiraptor feinbergi. The generic name is derived from Bambi, in reference to the young age of the specimen, and a Latin raptor, "seizer". The specific epithet honours Michael and Ann Feinberg who acquired the specimen from a fossil poacher and made it available to science. [4] In 2000 George Olshevsky suggested the emended epithet "feinbergorum", the plural genitive, and this was followed by some authors but such emendations are no longer allowed by the ICZN.
The holotype specimen AMNH FR 30556 (previously AMNH 001 and FIP 001, sometimes wrongly referred to as AMNH FR 30554), was uncovered in layers of the Upper Two Medicine Formation dating to the late Campanian. It is currently housed at the American Museum of Natural History, New York. It consists of a partially articulated largely complete skeleton with skull of a juvenile individual. Though the right side of the skeleton is damaged, most bones are uncompressed and well-preserved. The end of the tail is lacking. Also a paratype was assigned in 2000, FIP 002-136, consisting of thirty-four skeletal elements of at least two adult individuals found near the holotype. In 2004 an upper jaw bone was referred to the species, specimen MOR 553S-7-30-91-274. [5]
While adult specimens are known, only the type specimen, a juvenile, has been described. This juvenile Bambiraptor has a preserved length of 90 centimetres (3.0 ft), [6] and an estimated total length of one metre. It perhaps weighed only two kilograms (4.4 lb). It had long hindlimbs, indicating it could have been a fast runner. It also had very long arms and a well-developed wishbone. According to an SVP abstract published in 2021, the holotype is 30-40% the size of specimen MOR 553S-7-30-91-274. Directly scaling up the holotype specimen gives a length of 2.5-3.3 m. However, this is likely a low estimate since the specimen is a maxilla with proportions like that of the holotype, and juvenile animals tend to have proportionally longer skulls. In 2010 Gregory S. Paul estimated the adult length at 1.3 metres (4.3 ft), the weight at five kilogrammes. [7]
Research done by Phil Senter of the Lamar State College in Orange, Texas has indicated that Bambiraptor may have had mutually opposable first and third fingers and a forelimb maneuverability that would allow the hand to reach its mouth. [8] This would have given the animal the ability to "hold" food in its front limbs and place it in its mouth, in a similar manner to some modern-day small mammals. [9]
Bambiraptor had a brain size in the lower range of modern birds. Because of its enlarged cerebellum, which may indicate higher agility and higher intelligence than other dromaeosaurs, David A. Burnham has hypothesized that Bambiraptor feinbergi may have been arboreal. Life in the trees may have required evolutionary pressure that resulted in a larger brain. Burnham also offers an alternative hypothesis that a larger brain could be selected for as a result of hunting more agile prey items such as lizards and mammals. The Bambiraptor holotype had with 14 cm3 the largest brain for its size of any dinosaur yet discovered, although the brain size may be due to its age, because juvenile animals tend to have larger brain-to-body ratios compared to adults.
During the conference where Bambiraptor was first introduced, the dinosaur reconstruction specialist Brian Cooley portrayed Bambiraptor as having feathers, despite the fact that no feathers were found with the fossil itself. His decision was influenced by the fact that because Bambiraptor within a cladistic analysis was a member of a group, Paraves, that contained feathered true birds and that was the sister taxon of Oviraptorosauria, a group that also had feathered forms (e.g. Caudipteryx), Bambiraptor most likely had feathers too due to phylogenetic bracketing. Most paleontologists support Cooley's view, and subsequent discoveries [ citation needed ] confirmed that small dromaeosaurid dinosaurs like Bambiraptor were fully covered in feathers (see Dromaeosauridae for more information).
Bambiraptor was assigned to the Dromaeosauridae in 2000. Subsequent cladistic analyses differ in the position of Bambiraptor: it has been recovered in the Velociraptorinae, Microraptoria and most recently in the Saurornitholestinae.
Velociraptor is a genus of small dromaeosaurid dinosaurs that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis, named and described in 1924. Fossils of this species have been discovered in the Djadochta Formation, Mongolia. A second species, V. osmolskae, was named in 2008 for skull material from the Bayan Mandahu Formation, China.
Deinonychus is a genus of dromaeosaurid theropod dinosaur with one described species, Deinonychus antirrhopus. This species, which could grow up to 3.4 meters (11 ft) long, lived during the early Cretaceous Period, about 115–108 million years ago. Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland.
Dromaeosauridae is a family of feathered coelurosaurian theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek δρομαῖος (dromaîos), meaning 'running at full speed', 'swift', and σαῦρος (saûros), meaning 'lizard'. In informal usage, they are often called raptors, a term popularized by the film Jurassic Park; several genera include the term "raptor" directly in their name, and popular culture has come to emphasize their bird-like appearance and speculated bird-like behavior.
Dromaeosaurus is a genus of dromaeosaurid theropod dinosaur that lived during the Late Cretaceous period, sometime between 80 and 69 million years ago, in Alberta, Canada and the western United States. The type species is Dromaeosaurus albertensis, which was described by William Diller Matthew and Barnum Brown in 1922. Its fossils were unearthed in the Dinosaur Park Formation. Teeth attributed to this genus have been found in the Prince Creek Formation. Dromaeosaurus is the type genus of both Dromaeosauridae and Dromaeosaurinae, which include many genera with similar characteristics to Dromaeosaurus such as possibly its closest relative Dakotaraptor. Dromaeosaurus was heavily built, more so than other dromaeosaurs that are similar in size, like Velociraptor.
Sinornithosaurus is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period of the Yixian Formation in what is now China. It was the fifth non–avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago.
John Harold Ostrom was an American paleontologist who revolutionized the modern understanding of dinosaurs. Ostrom's work inspired what his pupil Robert T. Bakker has termed a "dinosaur renaissance".
Saurornitholestes is a genus of carnivorous dromaeosaurid theropod dinosaur from the late Cretaceous of Canada (Alberta) and the United States.
Ornitholestes is a small theropod dinosaur of the late Jurassic of Western Laurasia.
Adasaurus is a genus of dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous period about 70 million years ago. The genus is known from two partial specimens found in the Nemegt Formation of Mongolia that were partially described in 1983 by the paleontologist Rinchen Barsbold.
Achillobator is a genus of large dromaeosaurid theropod dinosaur that lived during the Late Cretaceous period about 96 million to 89 million years ago in what is now the Bayan Shireh Formation of Mongolia. The genus is currently monotypic, only including the type species A. giganticus. The first remains were found in 1989 during a Mongolian-Russian field expedition and later described in 1999. Remains at the type locality of Achillobator may represent additional specimens. It represents the first and largest dromaeosaurid known from the Bayan Shireh Formation.
Tenontosaurus is a genus of medium- to large-sized ornithopod dinosaur. It was a relatively medium sized ornithopod, reaching 6.5 to 8 meters in length and 600 to 1,000 kilograms in body mass. It had an unusually long, broad tail, which like its back was stiffened with a network of bony tendons.
Microvenator is a genus of dinosaur from the Early Cretaceous Cloverly Formation in what is now south central Montana. Microvenator was an oviraptorosaurian theropod. The holotype fossil is an incomplete skeleton, most likely a juvenile with a length of 1.3 m (4.3 ft), and consequently, the adult size remains uncertain. Microvenator celer is primitive and may be the "sister taxon to all other oviraptorosaurs."
Velociraptorinae is a subfamily of the theropod group Dromaeosauridae. The earliest velociraptorines are probably Nuthetes from the United Kingdom, and possibly Deinonychus from North America. However, several indeterminate velociraptorines have also been discovered, dating to the Kimmeridgian stage, in the Late Jurassic Period. These fossils were discovered in the Langenberg quarry, Oker near Goslar, Germany.
Hesperonychus was a small, carnivorous dinosaur. It was a member of the family Dromaeosauridae, along with its larger relatives Deinonychus and Velociraptor. There is one described species, Hesperonychus elizabethae. The type species was named in honor of Dr. Elizabeth Nicholls of the Royal Tyrrell Museum of Palaeontology who collected it as a student in 1982. It is known from fossils recovered from the lowermost strata of the Dinosaur Park Formation of Alberta, dating to the late Cretaceous about 76.5 million years ago. Though known from partial remains, researchers have estimated that it was a small dinosaur measuring about 1 metre (3.3 ft) long and weighing between 1.5 and 2 kilograms, making it the smallest carnivorous non-avian dinosaur known from North America.
Saurornitholestinae is a subfamily of the theropod group Dromaeosauridae. The saurornitholestines currently include three monotypic genera: Atrociraptor marshalli, Bambiraptor feinbergi, and Saurornitholestes langstoni. All are medium-sized dromaeosaurs from the Late Cretaceous of western North America. The group was originally recognized by Longrich and Currie as the sister taxon to a clade formed by the Dromaeosaurinae and Velociraptorinae. However, not all phylogenetic analyses recover this group and/or with the same proposed genera.
Tianyuraptor is a genus of short-armed dromaeosaurid dinosaur that lived during the Early Cretaceous, about 122 million years ago. Its remains have been found in western Liaoning, China. It was similar to other dromaeosaurids found in Liaoning, with the exception of being somewhat more primitive. The type specimen, formally named in 2009, shows features not seen in previously known Northern Hemisphere (Laurasian) dromaeosaurids, but present in Southern Hemisphere (Gondwanan) species and early birds. Because of this, the scientists who first studied Tianyuraptor described it as a "transitional species", bridging the gap between northern and southern types of dromaeosaurid. Tianyuraptor also differs from previously known dromaeosaurids in that it possesses a relatively small furcula ("wishbone"), and unusually short forelimbs.
This timeline of dromaeosaurid research is a chronological listing of events in the history of paleontology focused on the dromaeosaurids, a group of sickle-clawed, bird-like theropod dinosaurs including animals like Velociraptor. Since the Native Americans of Montana used the sediments of the Cloverly Formation to produce pigments, they may have encountered remains of the dromaeosaurid Deinonychus hundreds of years before these fossils came to the attention of formally trained scientists.
Dakotaraptor is a potentially chimaeric genus of large dromaeosaurid theropod dinosaur that lived in western North America during the Late Cretaceous period. The remains have been found in the Maastrichtian-aged Hell Creek Formation, dated to the very end of the Mesozoic era, making Dakotaraptor one of the last surviving dromaeosaurids. The remains of D. steini were discovered in a multi-species bonebed. Elements of the holotype and referred specimens were later found to belong to trionychid turtles and further analysis of potential non-dromaeosaurid affinities of the holotype and referred material have not yet been conducted. Phylogenetic analyses of D. steini place it in a variety of positions within Dromaeosauridae.
Wulong is a genus of microraptorine dromaeosaurid dinosaurs from the Early Cretaceous (Aptian) Jiufotang Formation of China. The genus includes a single species, Wulong bohaiensis. The skeletal remains, which include preserved feathers, represent a juvenile.
Dineobellator is a genus of dromaeosaurid theropod dinosaur that lived in North America during the Late Cretaceous period 68 million years ago. The remains have been found in the Maastrichtian stage of the Naashoibito Member at the Ojo Alamo Formation, New Mexico.