Gallimimus
Encyclopedia
Gallimimus is a genus
of ornithomimid theropod dinosaur
from the late Cretaceous
period (Maastrichtian
stage) Nemegt Formation
of Mongolia
. With individuals as long as 8 metres (26.2 ft), it was one of the largest ornithomimosaurs. Gallimimus is known from multiple individuals, ranging from juvenile (about 0.5 metres tall at the hip) to adult (about two metres tall at the hip).
The first fossil
remains of this dinosaur were discovered in early August 1963 by a team of Professor Zofia Kielan-Jaworowska
at Tsagan Khushu during a Polish-Mongolian expedition to the Gobi Desert
of Mongolia. The find was reported by her in 1965. In 1972, it was named and described by paleontologists Rinchen Barsbold, Halszka Osmólska
, and Ewa Roniewicz. The only named species is the type species
Gallimimus bullatus. The generic name is derived from Latin
gallus, "chicken", and mimus, "mimic", in reference to the neural arches of the front neck vertebrae which resemble those of the Galliformes
. The specific name is derived from Latin bulla
, a magic capsule worn by Roman youth around the neck, in reference to a bulbous swelling in the braincase on the underside of the parasphenoid, in the form of a capsule.
The holotype
specimen, IGM 100/11, consists of a partial skeleton including the skull and lower jaws. It is a larger skeleton; several other partial skeletons have been described, most of them of juveniles, and numerous single bones.
A second species announced by Barsbold in 1996, "Gallimimus mongoliensis" based on specimen IGM 100/14 from the older Bayanshiree Formation, has never been formally referred to this genus. In a reanalysis of the nearly complete skeleton of "Gallimimus mongoliensis" Barsbold concluded in 2006 that it is not a species of Gallimimus but may represent a new, currently unnamed ornithomimid genus.
-like, with a small head, toothless beak, large eyes, a long neck, short arms, long legs, and a long tail. A diagnostic character of Gallimimus is a distinctly short 'hand' relative to the humerus
length, when compared to other ornithomimids. The tail was used as a counter-balance. The eyes were located on the sides of its head, meaning that it did not possess binocular vision
. Like most modern birds and other theropods, it had hollow bones. Gallimimus had a number of adaptations which suggest good running ability, such as a strong ilium
, heavy tail base, long limbs, a long tibia
and metatarsus
and short toes, but it is unknown how fast it could run. All ornithomimids had long skulls but that of Gallimimus was exceptionally elongated, due to an elongation of the snout. The snouts of the juvenile specimens are much shorter.
Swedish researcher Jørn H. Hurum in 2001 published a detailed description of a complete lower jaw bone from Gallimimus bullatus. He noted new features in the "paper thin" jaw and corrects minor mistakes made in previous reconstructions of the lower jaw of G. bullatus. Hurum suggests that a "large widening of the anterior end of the prearticular" is an apomorphy for Gallimimus bullatus. He also notes that the tight intramandibular joint would prevent any movement between the front and rear portions of the lower jaw.
In 2001 Norell et al. reported a specimen of Gallimimus (IGM 100/1133): a skull with soft tissue preservation. This specimen, as well as another new fossil skull of Ornithomimus, had a keratinous beak with vertical grooves projecting from the bony upper mandible. These structures are reminiscent of the lamellae seen in ducks, in which they function to strain small edible items like plants, forams, mollusks, and ostracods from the water. The authors further noted that ornithomimids were abundant in mesic environments, and rarer in more arid environments, suggesting that they may have depended on waterborne sources of food, possibly filter feeding. They noted that primitive ornithomimids had well developed teeth, while derived forms were edentulous and probably could not feed on large animals.
One later paper questioned the conclusions of Norell et al. Barrett (2005) noted that vertical ridges are seen on the inner surface of the beaks of strictly herbivorous turtles, and also the hadrosaurid Edmontosaurus. Barrett also offered calculations, estimating how much energy could be derived from filter feeding and the probable energy needs of an animal as big as Gallimimus. He concluded that herbivory was more likely.
Gallimimus appeared in the motion picture Jurassic Park
. A flock was seen running across a vast field from a Tyrannosaurus
, which attacked and killed one of the ornithomimids. Gallimimus is also featured in the film's first sequel, The Lost World: Jurassic Park
, during the 'roundup' sequence.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of ornithomimid theropod dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
from the late Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period (Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
stage) Nemegt Formation
Nemegt Formation
The Nemegt Formation is a geological formation dating from the Late Cretaceous sedimentary from the Gobi Desert of Mongolia. It overlies and sometimes forms folds with the Barun Goyot Formation. It consists of river channel sediments and contains fossils of fish, turtles, crocodilians, birds and a...
of Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
. With individuals as long as 8 metres (26.2 ft), it was one of the largest ornithomimosaurs. Gallimimus is known from multiple individuals, ranging from juvenile (about 0.5 metres tall at the hip) to adult (about two metres tall at the hip).
Discovery
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
remains of this dinosaur were discovered in early August 1963 by a team of Professor Zofia Kielan-Jaworowska
Zofia Kielan-Jaworowska
Zofia Kielan-Jaworowska is a Polish paleobiologist. In the mid-1960s Kielan-Jaworowska led a series of Polish-Mongolian paleontological expeditions to the Gobi Desert...
at Tsagan Khushu during a Polish-Mongolian expedition to the Gobi Desert
Gobi Desert
The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the...
of Mongolia. The find was reported by her in 1965. In 1972, it was named and described by paleontologists Rinchen Barsbold, Halszka Osmólska
Halszka Osmólska
Halszka Osmólska was a Polish paleontologist who had specialized in Mongolian dinosaurs.She was born in Poznań. A member of the 1965 and 1970 Polish–Mongolian expeditions to the Gobi Desert, she described many finds from these rocks, often with Teresa Maryańska...
, and Ewa Roniewicz. The only named species is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
Gallimimus bullatus. The generic name is derived from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
gallus, "chicken", and mimus, "mimic", in reference to the neural arches of the front neck vertebrae which resemble those of the Galliformes
Galliformes
Galliformes are an order of heavy-bodied ground-feeding domestic or game bird, containing turkey, grouse, chicken, New and Old World Quail, ptarmigan, partridge, pheasant, and the Cracidae. Common names are gamefowl or gamebirds, landfowl, gallinaceous birds or galliforms...
. The specific name is derived from Latin bulla
Bulla (amulet)
Bulla, an amulet worn like a locket, was given to male children in Ancient Rome nine days after birth. They were enigmatic objects of lead covered in gold foil. A bulla was worn around the neck as a locket to protect against evil spirits and forces. A bulla was made of differing substances...
, a magic capsule worn by Roman youth around the neck, in reference to a bulbous swelling in the braincase on the underside of the parasphenoid, in the form of a capsule.
The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen, IGM 100/11, consists of a partial skeleton including the skull and lower jaws. It is a larger skeleton; several other partial skeletons have been described, most of them of juveniles, and numerous single bones.
A second species announced by Barsbold in 1996, "Gallimimus mongoliensis" based on specimen IGM 100/14 from the older Bayanshiree Formation, has never been formally referred to this genus. In a reanalysis of the nearly complete skeleton of "Gallimimus mongoliensis" Barsbold concluded in 2006 that it is not a species of Gallimimus but may represent a new, currently unnamed ornithomimid genus.
Description
Gallimimus was rather ostrichOstrich
The Ostrich is one or two species of large flightless birds native to Africa, the only living member of the genus Struthio. Some analyses indicate that the Somali Ostrich may be better considered a full species apart from the Common Ostrich, but most taxonomists consider it to be a...
-like, with a small head, toothless beak, large eyes, a long neck, short arms, long legs, and a long tail. A diagnostic character of Gallimimus is a distinctly short 'hand' relative to the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
length, when compared to other ornithomimids. The tail was used as a counter-balance. The eyes were located on the sides of its head, meaning that it did not possess binocular vision
Binocular vision
Binocular vision is vision in which both eyes are used together. The word binocular comes from two Latin roots, bini for double, and oculus for eye. Having two eyes confers at least four advantages over having one. First, it gives a creature a spare eye in case one is damaged. Second, it gives a...
. Like most modern birds and other theropods, it had hollow bones. Gallimimus had a number of adaptations which suggest good running ability, such as a strong ilium
Ilium
-Places:* Ilion or, Latinized, Ilium, another name for the legendary city of Troy, hence the title of Homer's Iliad*Ilium , an ancient city in Epirus...
, heavy tail base, long limbs, a long tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
and metatarsus
Metatarsus
The metatarsus or metatarsal bones are a group of five long bones in the foot located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side : the first, second, third, fourth, and fifth...
and short toes, but it is unknown how fast it could run. All ornithomimids had long skulls but that of Gallimimus was exceptionally elongated, due to an elongation of the snout. The snouts of the juvenile specimens are much shorter.
Swedish researcher Jørn H. Hurum in 2001 published a detailed description of a complete lower jaw bone from Gallimimus bullatus. He noted new features in the "paper thin" jaw and corrects minor mistakes made in previous reconstructions of the lower jaw of G. bullatus. Hurum suggests that a "large widening of the anterior end of the prearticular" is an apomorphy for Gallimimus bullatus. He also notes that the tight intramandibular joint would prevent any movement between the front and rear portions of the lower jaw.
Phylogeny
Gallimimus was in 1972 assigned to the Ornithomimidae. This is confirmed by recent cladistic analyses.Beak and Paleoecology
The feeding habits of ornithomimids have been controversial. The original describers thought Gallimimus preyed upon small animals, using its long arms as rakes to remove covering plant material on the soil. Later suggestions included omnivory and herbivory.In 2001 Norell et al. reported a specimen of Gallimimus (IGM 100/1133): a skull with soft tissue preservation. This specimen, as well as another new fossil skull of Ornithomimus, had a keratinous beak with vertical grooves projecting from the bony upper mandible. These structures are reminiscent of the lamellae seen in ducks, in which they function to strain small edible items like plants, forams, mollusks, and ostracods from the water. The authors further noted that ornithomimids were abundant in mesic environments, and rarer in more arid environments, suggesting that they may have depended on waterborne sources of food, possibly filter feeding. They noted that primitive ornithomimids had well developed teeth, while derived forms were edentulous and probably could not feed on large animals.
One later paper questioned the conclusions of Norell et al. Barrett (2005) noted that vertical ridges are seen on the inner surface of the beaks of strictly herbivorous turtles, and also the hadrosaurid Edmontosaurus. Barrett also offered calculations, estimating how much energy could be derived from filter feeding and the probable energy needs of an animal as big as Gallimimus. He concluded that herbivory was more likely.
In popular culture
Jurassic Park (film)
Jurassic Park is a 1993 American science fiction adventure film directed by Steven Spielberg. The film is based on the novel of the same name by Michael Crichton. It stars Sam Neill, Laura Dern, Jeff Goldblum, Richard Attenborough, Martin Ferrero, and Bob Peck...
. A flock was seen running across a vast field from a Tyrannosaurus
Tyrannosaurus
Tyrannosaurus meaning "tyrant," and sauros meaning "lizard") is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex , commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other...
, which attacked and killed one of the ornithomimids. Gallimimus is also featured in the film's first sequel, The Lost World: Jurassic Park
The Lost World: Jurassic Park
The Lost World: Jurassic Park is a 1997 science fiction thriller film, directed by Steven Spielberg. The film was produced by Bonnie Curtis, Kathleen Kennedy, Gerald R. Molen and Colin Wilson...
, during the 'roundup' sequence.