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Encyclopedia > Tyrannosaurus rex
iTyrannosaurus
Fossil range: Late Cretaceous
Fossil skeleton atNational Museum of Natural History, Washington, D.C.
Conservation status
Extinct (fossil)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Tyrannosauridae
Subfamily: Tyrannosaurinae
Genus: Tyrannosaurus
Osborn, 1905
Species: T. rex
Binomial name
Tyrannosaurus rex
Osborn, 1905
Synonyms

Manospondylus gigas
Dynamosaurus imperiosus
Dinotyrannus megagracilis
Nanotyrannus lancensis?
Geography of the US in the late Cretaceous Late Cretaceous (also called the Upper Cretaceous) refers to the second half of the Cretaceous period, named after the famous white chalk cliffs of southern England, which date from this time. ... Image File history File links Download high resolution version (1026x1267, 345 KB) Tyrannosaurus rex skeleton at the Smithsonian museum of Natural History Edited version of http://commons. ... The museum as seen from the National Mall, the Old Post Office Building visible in the distance National Mall museum entrance The National Museum of Natural History is a museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C. The museums collections total over... Nickname: DC, The District Motto: Justitia Omnibus (Justice for All) Location of Washington, D.C., in relation to the states Maryland and Virginia Coordinates: Federal District District of Columbia Mayor Adrian M. Fenty (D) City Council Chairperson: Vincent C. Gray (D) Ward 1: Jim Graham (D) Ward 2: Jack Evans... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... An ammonite fossil Eocene fossil fish of the genus Knightia Petrified wood fossil formed through permineralization. ... For other uses, see Scientific classification (disambiguation). ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Xenoturbellida Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Ectoprocta Bryozoa... {{{subdivision_ranks}}} See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Clades Subclass Anapsida Subclass Diapsida Infraclass Lepidosauromorpha Infraclass Archosauromorpha Sauropsids are a diverse group of mostly egg-laying vertebrate animals. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Groups Sauropodomorpha    Saturnalia    Prosauropoda    Sauropoda Theropoda    Eoraptor    Herrerasauridae    Ceratosauria    Tetanurae       Aves(extant) Saurischians (from the Greek Saurischia meaning lizard hip) are one of the two orders/branches of dinosaurs. ... Subdivisions ?Eoraptor Herrerasauria Coelophysoidea Ceratosauria Cryolophosaurus Spinosauridae Carnosauria Coelurosauria Theropods (beast foot) are a group of bipedal saurischian dinosaurs. ... Genera See text. ... Henry Fairfield Osborn (August 8, 1857 — November 6, 1935) was an American paleontologist and geologist. ... In biology, binomial nomenclature is the formal method of naming species. ... Henry Fairfield Osborn (August 8, 1857 — November 6, 1935) was an American paleontologist and geologist. ... In scientific nomenclature, synonyms are different scientific names used for a single taxon. ...

Tyrannosaurus (IPA pronunciation /taɪˌɹænəˈsɔrəs/ or /tɪ-/; from the Greek "τυραννόσαυρος", meaning 'tyrant lizard') is a genus of tyrannosaurid theropod dinosaur. The species Tyrannosaurus rex, commonly abbreviated to T. rex, is one of the dinosaurs most often featured in popular culture around the world. It hails from what is now western North America. Some scientists consider Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus, while others maintain Tarbosaurus as a separate genus. This is a concise version of the International Phonetic Alphabet for English sounds. ... For other uses of the word, please see Genus (disambiguation). ... Genera Albertosaurus Daspletosaurus Gorgosaurus Tarbosaurus Tyrannosaurus The tyrannosaurids were a family of dinosaurs whose name is derived from the Greek words trannos, meaning tyrant; and sauros, meaning lizard. ... Families See text Theropods (beast foot) are a group of bipedal, primarily carnivorous dinosaurs, belonging to the saurischian (lizard-hip) family. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... In biology, a species is one of the basic units of biodiversity. ... Popular culture, or pop culture, (literally: the culture of the people) consists of widespread cultural elements in any given society. ... World map showing North America A satellite composite image of North America. ... Binomial name Tarbosaurus bataar Maleev, 1955 Tarbosaurus, meaning Terror Lizard (from the Greek tarbos/ταρβος meaning fright, alarm, terror (interestingly it can also mean awe or reverence[1]) and saurus/σαυρος meaning lizard), was a member of the dinosaur family of tyrannosaurids, which flourished during the early Maastrichtian of the Late Cretaceous... World map showing the location of Asia. ...


Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small and retained only two digits. Although other theropods rivaled or exceeded T. rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring over 12 metres (40 feet) in length and up to 7.5 tons in weight. This article or section does not cite its references or sources. ... This tigers sharp teeth and strong jaws are the classical physical traits expected from carnivorous mammalian predators A carnivore (IPA: ), meaning meat eater (Latin carne meaning flesh and vorare meaning to devour), is an animal that eats a diet consisting mainly of meat, whether it comes from live animals... It has been suggested that temporal fenestra be merged into this article or section. ... This article, image, template or category belongs in one or more categories. ... The metre, or meter (U.S.), is a measure of length. ... A foot (plural: feet; symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... A tonne (also called metric ton) is a non-SI unit of mass, accepted for use with SI, defined as: 1 tonne = 103 kg (= 106 g). ...


Fossils of some T. rex have been found in North American rock formations dating to the very end of the Cretaceous Period (late Maastrichtian stage, 65 million years ago); it was among the last dinosaurs to exist prior to the Cretaceous-Tertiary extinction event. More than 30 specimens of T. rex have now been identified, some nearly complete, which has allowed significant research into many aspects of its biology, including its life history and biomechanics. The feeding habits and potential speed of T. rex remain controversial. An ammonite fossil Eocene fossil fish of the genus Knightia Petrified wood fossil formed through permineralization. ... A geologic formation is a formally named rock stratum or geological unit. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... A geologic period is a subdivision of geologic time that divides Eras into smaller timeframes. ... The Maastrichtian is the last age of the Cretaceous period, and therefore of the Mesozoic era. ... Badlands near Drumheller, Alberta where erosion has exposed the KT boundary. ... Biology (from Greek Βìο meaning life and Λoγος meaning the study of, see below) is the study of life. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Contents

Description

The size of Tyrannosaurus, compared with a 1.8 m (approx. 6 ft) human
The size of Tyrannosaurus, compared with a 1.8 m (approx. 6 ft) human

Tyrannosaurus rex was one of the largest land carnivores of all time, about 12 to 13 meters (40 to 43.3 feet) long, and 4.5-5 m (14-16.6 ft) tall, when fully-grown.[1] Mass estimates have varied widely over the years, from more than 7,200 kilograms (8 short tons),[2] to less than 4,500 kg (5 tons),[3][4] with most modern estimates ranging between 5,400 and 6,800 kg (between 6 and 7.5 tons).[5][6][7][8] Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... The metre, or meter (symbol: m) is the SI base unit of length. ... A foot (plural: feet; symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et... The short ton is a unit of mass equal to 907. ...


The largest known T. rex skulls measure up to 1.5 m (5 ft) in length. Compared to other theropods, the skull was heavily modified. The skull was extremely wide posteriorly, with a narrow snout, allowing some degree of binocular vision. Some of the bones, such as the nasals, were fused, preventing movement between them. Large fenestrae (openings) in the skull reduced weight and provided areas for muscle attachment. The bones themselves were massive, as were the serrated teeth which, rather than being bladelike, were oval in cross-section. Like other tyrannosaurids, T. rex displayed marked heterodonty, with the premaxillary teeth at the front of the upper jaw closely-packed and D-shaped in cross-section. Large bite marks found on bones of other dinosaurs indicate that these teeth could penetrate solid bone. T. rex had the greatest bite force of any dinosaur and one of the strongest bite forces of any animal. Worn or broken teeth are often found, but unlike those of mammals, tyrannosaurid teeth were continually replaced throughout the life of the animal.[1] Binocular vision is vision in which both eyes are used synchronously to produce a single image. ... Grays Anatomy illustration of a human femur. ... The Nasal Bones (Ossa Faciei & Ossa Nasalia) are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, the bridge of the nose. ... The anatomical term heterodont (different teeth) refers to animals which possess more than a single tooth morphology. ... The premaxilla is a pair of small bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. ... Subclasses Allotheria* Order Multituberculata (extinct) Order Volaticotheria (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Prototheria Order Monotremata Theria Infraclass Marsupialia Infraclass Eutheria The mammals are the class of vertebrate animals characterized by the production of milk in females for the nourishment of young, from mammary glands present on most species...


The neck of T. rex formed a natural S-shaped curve like that of other theropods, but was short and muscular to support the massive head. The two-fingered forelimbs were very small relative to the size of the body, but heavily built. In contrast, the hindlimbs were among the longest in proportion to body size of any theropod. The tail was heavy and long, sometimes containing over forty vertebrae, in order to balance the massive head and torso. To compensate for the immense bulk of the animal, many bones throughout the skeleton were hollow. This reduced the weight of the skeleton while maintaining much of the strength of the bones.[1] A diagram of a thoracic vertebra. ...


Classification

T. rex head reconstruction at the Oxford University Museum of Natural History
T. rex head reconstruction at the Oxford University Museum of Natural History

Tyrannosaurus is the type genus of the superfamily Tyrannosauroidea, the family Tyrannosauridae, and the subfamily Tyrannosaurinae. Other members of the tyrannosaurine subfamily include the North American Daspletosaurus and the Asian Tarbosaurus,[9][10] both of which have occasionally been synonymized with Tyrannosaurus.[11] Tyrannosaurids were once commonly thought to be descendants of earlier large theropods such as megalosaurs and carnosaurs, although more recently they were reclassified with the generally smaller coelurosaurs.[12] Image File history File linksMetadata Download high resolution version (2560x1920, 2280 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high resolution version (2560x1920, 2280 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... The Oxford University Museum of Natural History, sometimes known simply as the Oxford University Museum, is a museum displaying many of the University of Oxfords natural history specimens. ... Genera See text. ... Image comparing the size of Daspletosaurus and a human. ... World map showing the location of Asia. ... Families Spinosauridae Megalosauridae Megalosauroidea was a superfamily of tetanuran theropod dinosaurs that lived from the Middle Jurassic to the Late Cretaceous period. ... Families Allosauridae    Allosaurinae    ?Carcharodontosaurinae Sinraptoridae Carnosauria is a sub-group of Theropoda, a group of predatory dinosaurs. ... Subclades Nqwebasaurus Proceratosaurus Tyrannoraptora ?Coeluridae ?Compsognathidae Tyrannosauroidea Maniraptoriformes [incertae sedis] Alvarezsauridae Maniraptora Ornithomimosauria Coelurosauria is a group of theropod dinosaurs that includes the subgroups Tyrannosauridae, Ornithomimidae, and Maniraptora. ...


In 1955, Soviet paleontologist Evgeny Maleev named a new species, Tyrannosaurus bataar, from Mongolia.[13] By 1965, this species had been renamed Tarbosaurus bataar.[14] Despite the renaming, many phylogenetic analyses have found Tarbosaurus bataar to be the sister taxon of Tyrannosaurus rex,[10] and it has often been considered an Asian species of Tyrannosaurus.[12][15][16] However, a recent redescription of the skull of Tarbosaurus bataar has shown that it was much narrower than that of Tyrannosaurus rex and that during a bite, the distribution of stress in the skull would have been very different, closer to that of Alioramus, another Asian tyrannosaur.[17] A related cladistic analysis found that Alioramus, not Tyrannosaurus, was the sister taxon of Tarbosaurus, which, if true, would suggest that Tarbosaurus and Tyrannosaurus should remain separate.[9] Motto: Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) Translation: Workers of the world, unite!) Anthem: The Internationale (1922-1944) Hymn of the Soviet Union (1944-1991) Capital (and largest city) Moscow Official languages None; Russian de facto Government Socialist Republic/Federation of Soviet Republics  - Last President Mikhail Gorbachev  - Last Premier Ivan Silayev... Paleontology or palaeontology (see Spelling differences) is the study of the history and development of life on Earth, including that of ancient plants and animals, based on the fossil record (evidence of their prehistoric existence as typically preserved in sedimentary rocks). ... Evgeny Aleksandrovich Maleev (Russian: ; 1915-1966) (pronounced Malay-ev)) was a Russian paleontologist who named the armoured dinosaur Talarurus, the fearsome Tarbosaurus, and Therizinosaurus. ... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... This cladogram shows the relationship among various insect groups. ... Alioramus (Alioramus remotus) was a tyrannosaurid from Mongolia. ... Greek clados = branch) or phylogenetic systematics is a branch of biology that determines the evolutionary relationships of living things based on derived similarities. ...


Other tyrannosaurid fossils found in the same formations as T. rex were originally classified as separate taxa, including Aublysodon and "Albertosaurus" megagracilis.[11] However, these fossils are now universally considered to belong to juvenile T. rex.[18] A small but nearly complete skull from Montana, 60 cm (2 ft) long, may be an exception. This skull was originally classified as a species of Gorgosaurus ("G." lancensis) by Charles W. Gilmore in 1946,[19] but was later referred to a new genus, Nanotyrannus.[20] Opinions remain divided on the validity of N. lancensis. Many paleontologists consider the skull to belong to a juvenile T. rex.[21] There are minor differences between the two species, including the higher number of teeth in N. lancensis, which lead some scientists to recommend keeping the two genera separate until further research or discoveries clarify the situation.[10][22] Binomial name Gorgosaurus libratus Lambe, 1914 Gorgosaurus (Latin for dragon lizard) is a genus of carnivorous dinosaur that reached 7 to 8 meters (27 to 30 feet) in length, and weighed 2. ... Charles Whitney Gilmore (1874-1945) was an American paleontologist, who named dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus and Thescelosaurus. ... Binomial name Nanotyrannus lancensis Bakker, Currie & Williams, 1988 Nanotyrannus (tiny tyrant) was erected in 1988 for a small tyrannosaurid skull, previously described in 1946 (Gilmore) as Albertosaurus lancensis. ...


Manospondylus controversy

Skull of T. rex, type specimen at the Carnegie Museum of Natural History. This was heavily and inaccurately restored with plaster after Allosaurus, and has since been disassembled.
Skull of T. rex, type specimen at the Carnegie Museum of Natural History. This was heavily and inaccurately restored with plaster after Allosaurus, and has since been disassembled.

The first fossil specimen which can be attributed to Tyrannosaurus rex consists of two partial vertebrae (one of which has been lost) found by Edward Drinker Cope in 1892 and described as Manospondylus gigas. Osborn recognized the similarity between M. gigas and T. rex as early as 1917 but, due to the fragmentary nature of the Manospondylus vertebrae, he could not synonymize them conclusively.[23] Download high resolution version (875x589, 547 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (875x589, 547 KB) Wikipedia does not have an article with this exact name. ... The Carnegie Museums of Pittsburgh are operated by the Carnegie Institute and located in Pittsburgh, Pennsylvania. ... Species type (Marsh, 1878) Paul, 1987 Mateus , 2006 jimmadseni Chure, 2000 vide Glut, 2003 Synonyms Creosaurus Marsh, 1878 Labrosaurus Marsh, 1879 Camptonotus Marsh, 1879  ?Antrodemus Leidy, 1870  ?Epanterias Cope, 1878  ?Saurophaganax Chure, 1995 Allosaurus (IPA: ) was a large bipedal carnivorous dinosaur up to 12 m (39 ft) long. ... Edward Drinker Cope Edward Drinker Cope (July 28, 1840–April 12, 1897) was an American paleontologist and comparative anatomist. ...


Controversy erupted in June 2000 after more tyrannosaur bones unearthed in South Dakota by the Black Hills Institute were found at the type locality of M. gigas and judged to represent further remains of the same individual. These more recently-discovered remains clearly belong to T. rex. According to the rules of the International Commission on Zoological Nomenclature, the system that governs the scientific naming of animals, Manospondylus gigas should therefore have priority over Tyrannosaurus rex, because it was named first.[24] However, in the Fourth Edition of the International Code of Zoological Nomenclature, which took effect on January 1, 2000, Chapter 6, Article 23.9 states that "the prevailing usage must be maintained" when "the senior synonym or homonym has not been used as a valid name after 1899" and "the junior synonym or homonym has been used for a particular taxon, as its presumed valid name, in at least 25 works, published by at least 10 authors in the immediately preceding 50 years..." Tyrannosaurus rex more than qualifies as the valid name under these conditions and is considered a nomen protectum ("protected name") under the ICZN, making Manospondylus gigas a nomen oblitum ("forgotten name").[25][26] The International Code of Zoological Nomenclature is a set of rules in zoology that have one fundamental aim: to provide the maximum universality and continuity in classifying all animals according to taxonomic judgment. ... January 1 is the first day of the calendar year in both the Julian and Gregorian calendars. ... This article is about the year 2000. ... // A conserved name or nomen conservandum (plural nomina conservanda) is a scientific name that enjoys special nomenclatural protection. ... A nomen oblitum (Latin for forgotten name) is a name that has not been used in the scientific community for more than fifty years after its original proposal. ...


Paleobiology

As with all dinosaurs known only from the fossil record, much of Tyrannosaurus biology, including behavior, coloration, ecology, and physiology, remains unknown. However, many new specimens have been discovered in the last twenty years, which has allowed some informed speculation on growth patterns, sexual dimorphism, biomechanics, and metabolism. It has been suggested that this article or section be merged into Fossil. ... Ernst Haeckel coined the term oekologie in 1866. ... Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ...


Life history

A graph showing the hypothesized growth curves (body mass versus age) of four tyrannosaurids. Tyrannosaurus rex is drawn in black. Based on Erickson et al. 2004
A graph showing the hypothesized growth curves (body mass versus age) of four tyrannosaurids. Tyrannosaurus rex is drawn in black. Based on Erickson et al. 2004

The identification of several specimens as juvenile Tyrannosaurus rex has allowed scientists to document ontogenetic changes in the species, estimate the lifespan, and determine how quickly the animals would have grown. The smallest known individual (LACM 28471, the so-called "Jordan theropod") is estimated to have weighed only 29.9 kg (66 lb), while the largest, such as FMNH PR2081 ("Sue") most likely weighed over 5400 kg (6 short tons). Histologic analysis of T. rex bones showed LACM 28471 had aged only 2 years when it died, while "Sue" was 28 years old, an age which may have been close to the maximum for the species.[8] Image File history File links Tyrantgraph. ... Image File history File links Tyrantgraph. ... Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. ... The short ton is a unit of mass equal to 2000 lb (exactly 907. ... A thin section of lung tissue stained with hematoxylin and eosin. ...


Histology has also allowed the age of other specimens to be determined. Growth curves can be developed when the ages of different specimens are plotted on a graph along with their mass. A T. rex growth curve is S-shaped, with juveniles remaining under 1800 kg (2 short tons) until approximately 14 years of age, when body size began to increase dramatically. During this rapid growth phase, a young T. rex would gain an average of 600 kg (1600 lb) a year for the next four years. At 18 years of age, the curve plateaus again, indicating that growth slowed dramatically. For example, only 600 kg (1,300 lb) separated the 28-year-old "Sue" from a 22-year-old Canadian specimen (RTMP 81.12.1).[8] This sudden change in slope of the growth curve may indicate physical maturity, a hypothesis which is supported by the discovery of medullary tissue in the femur of a 16 to 20-year-old T. rex from Montana (MOR 1125, also known as "B-rex").[27] Medullary tissue is found only in female birds during ovulation, indicating that "B-rex" was of reproductive age. Other tyrannosaurids exhibit extremely similar growth curves, although with lower growth rates corresponding to their lower adult sizes.[28] The femur or thigh bone is the longest, most voluminous, and strongest bone of the human body. ...


Over half of the known T. rex specimens appear to have died within six years of reaching sexual maturity, a pattern which is also seen in other tyrannosaurs and in large, long-lived birds and mammals today. These species are characterized by high infant mortality rates, followed by relatively low mortality among juveniles. Mortality increases again following sexual maturity, partly due to the stresses of reproduction. One study suggests that the rarity of juvenile T. rex fossils is due in part to low juvenile mortality rates; the animals were not dying in large numbers at these ages, and so were not often fossilized. However, this rarity may also be due to the incompleteness of the fossil record or to the bias of fossil collectors towards larger, more spectacular specimens.[28] It has been suggested that this article or section be merged into Fossil. ...


Sexual dimorphism

As the number of specimens increased, scientists began to analyze the variation between individuals and discovered what appeared to be two distinct body types, or morphs, similarly to some other theropod species. As one of these morphs was more solidly built, it was termed the 'robust' morph while the other was termed 'gracile.' Several morphological differences associated with the two morphs were used to analyze sexual dimorphism in Tyrannosaurus rex, with the 'robust' morph usually suggested to be female. For example, the pelvis of several 'robust' specimens seemed to be wider, perhaps to allow the passage of eggs.[29] Comparative anatomy is the study of similarities and differences in organisms. ... Female (left) and male Common Pheasant, illustrating the dramatic difference in both color and size between the sexes Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. ... The pelvis (pl. ...

Outdated reconstruction (by Charles R. Knight), showing 'tripod' pose
Outdated reconstruction (by Charles R. Knight), showing 'tripod' pose

It was also thought that 'robust' animals possessed a reduced chevron on the first tail vertebra, also ostensibly to allow eggs to pass out of the reproductive tract, as had been reported for crocodiles.[30] However, in recent years, evidence for sexual dimorphism has been weakened. A full-sized chevron was discovered on the first tail vertebra of "Sue," an extremely robust individual, indicating that this feature could not be used to differentiate the two morphs. In 2005, it was reported that crocodiles exhibited no sexual dimorphism in chevron anatomy either, further weakening the case for dimorphism between T. rex sexes.[31] As T. rex specimens have been found from Saskatchewan to New Mexico, differences between individuals may be more indicative of geographic variation rather than sexual dimorphism. The differences could also be age-related, with 'robust' individuals being older animals.[1] Image File history File links Tyrannosaurusrex01. ... Image File history File links Tyrannosaurusrex01. ... Allosaurus by Charles R. Knight. ... Chevron bones are a series of bones on the underside of the tail of reptiles. ... A reproductive system is the ensembles and interactions of organs and/or substances within an organism that strictly pertain to reproduction. ... Motto: Multis E Gentibus Vires (Latin: From many peoples, strength) Official languages English Flower Western Red Lily Tree Paper Birch Bird Sharp-tailed Grouse Capital Regina Largest city Saskatoon Lieutenant-Governor Gordon Barnhart Premier Lorne Calvert (NDP) Parliamentary representation  - House seats  - Senate seats 14 6 Area Total  - Land  - Water  (% of... Capital Santa Fe Largest city Albuquerque Area  Ranked 5th  - Total 121,665 sq mi (315,194 km²)  - Width 342 miles (550 km)  - Length 370 miles (595 km)  - % water 0. ...


Only a single T. rex specimen has been conclusively shown to belong to a specific gender. Examination of "B-rex," the geologically oldest known specimen, demonstrated the preservation of soft tissue within several bones. Some of this tissue has been identified as medullary tissue, a specialized tissue grown only in modern birds as a source of calcium for the production of eggshell during ovulation. As only female birds lay eggs, medullary tissue is only found naturally in females, although males are capable of producing it when injected with female reproductive hormones like estrogen. This strongly suggests that "B-rex" was female, and that she died during ovulation. The presence of medullary tissue also provides further evidence of the close evolutionary relationship between birds and theropod dinosaurs.[27] A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Estriol. ...


Posture

Replica at Senckenberg Museum, showing modern view of posture
Replica at Senckenberg Museum, showing modern view of posture

Like many bipedal dinosaurs, Tyrannosaurus rex was historically depicted as a 'living tripod', with the body at 45 degrees or less from the vertical and the tail dragging along the ground, similar to a kangaroo. This concept dates from Joseph Leidy's 1865 reconstruction of Hadrosaurus, the first to depict a dinosaur in a bipedal posture.[32] Henry Fairfield Osborn, former president of the American Museum of Natural History (AMNH) in New York City, who believed the creature stood upright, further reinforced the notion after unveiling the first complete T. rex skeleton in 1915. It stood in this upright pose for nearly a century, until it was dismantled in 1992.[33] By 1970, scientists realized this pose was incorrect and could not have been maintained by a living animal, as it would have resulted in the dislocation or weakening of several joints, including the hips and the articulation between the head and the spinal column.[34] Despite its inaccuracies, the AMNH mount inspired similar depictions in many films and paintings (such as Rudolph Zallinger's famous mural The Age Of Reptiles in Yale University's Peabody Museum of Natural History) until the 1990s, when films such as Jurassic Park introduced a more accurate posture to the general public. Modern representations in museums, art, and film show T. rex with its body approximately parallel to the ground and tail extended behind the body to balance the head.[11] There have been suggestions that, when chasing prey, the animal might have raised its neck into an 'S' position (much like that of a bird) in order to avoid problems in changing direction; this was discussed in The Truth About Killer Dinosaurs. This way, the head might not always have been jutting forwards. Image File history File links Description: a plastik of a tyrannosaurus in front of the senckenberg. ... Image File history File links Description: a plastik of a tyrannosaurus in front of the senckenberg. ... T. Rex The Senckenberg Museum in Frankfurt is the largest museum of natural history in Germany. ... Look up tripod in Wiktionary, the free dictionary. ... This is the current Australian Collaboration of the Fortnight! Please help improve it to featured article standard. ... Joseph Leidy (1823–1891) was an American paleontologist. ... Binomial name Hadrosaurus foulkii Leidy, 1858 Hadrosaurus (Greek:sturdy lizard) is a hadrosaurid dinosaur genus. ... Henry Fairfield Osborn (August 8, 1857 — November 6, 1935) was an American paleontologist and geologist. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... Nickname: Big Apple, Gotham Location in the state of New York Coordinates: Country United States State New York Boroughs The Bronx Brooklyn Manhattan Queens Staten Island Settled 1613 Mayor Michael Bloomberg (R) Area    - City 1,214. ... Dislocation (joint dislocation) occurs when bones at a joint move from their normal position. ... A joint (from French joint) (articulation) is the location at which two bones make contact (articulate). ... The spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). ... Yale redirects here. ... The Peabody Museum of Natural History at Yale University was founded by the philanthropist George Peabody in 1866 at the behest of his nephew Othniel Charles Marsh, the early paleontologist. ... Jurassic Park is a novel written by Michael Crichton that was published in 1990. ... The Truth About Killer Dinosaurs is a two-part BBC documentary, presented by Bill Oddie, in which a group of scientists test out the strength of dinosaur weaponry using biomechanics. ...


Arms

Closeup of forelimb; specimen at National Museum of Natural History, Washington, DC

When Tyrannosaurus rex was first discovered, the humerus was the only element of the forelimb known.[35] For the initial mounted skeleton as seen by the public in 1915, Osborn substituted longer, three-fingered forelimbs like those of Allosaurus.[23] However, a year earlier, Lawrence Lambe described the short, two-fingered forelimbs of the closely-related Gorgosaurus.[36] This strongly suggested that T. rex had similar forelimbs, but this hypothesis was not confirmed until the first complete T. rex forelimbs were identified in 1989, belonging to MOR 555 (the "Wankel rex").[37] The remains of "Sue" also include complete forelimbs.[1] T. rex 'arms' are very small relative to overall body size, measuring only 1 m (3 ft 3 in) long. However, they are not vestigial but instead show large areas for muscle attachment, indicating considerable strength. This was recognized as early as 1906 by Osborn, who speculated that the forelimbs may have been used to grasp a mate during copulation.[38] It has also been suggested that the forelimbs were used to assist the animal in rising from a prone position.[34] Another possibility is that the forelimbs held struggling prey while it was dispatched by the tyrannosaur's enormous jaws. This hypothesis may be supported by biomechanical analysis. T. rex forelimb bones exhibit extremely thick cortical bone, indicating that they were developed to withstand heavy loads. The biceps brachii muscle of a full-grown Tyrannosaurus rex was capable of lifting 199 kg (438 lb) by itself; this number would only increase with other muscles (like the brachialis) acting in concert with the biceps. A T. rex forearm also had a reduced range of motion, with the shoulder and elbow joints allowing only 40 and 45 degrees of motion, respectively. In contrast, the same two joints in Deinonychus allow up to 88 and 130 degrees of motion, respectively, while a human arm can rotate 360 degrees at the shoulder and move through 165 degrees at the elbow. The heavy build of the arm bones, extreme strength of the muscles, and limited range of motion may indicate a system designed to hold fast despite the stresses of a struggling prey animal.[39] Closeup of arm of Tyrannosaurus rex fossil at the National Museum of Natural History, Washington, DC; digital photo by User:Postdlf, 2/20/05 File links The following pages link to this file: Tyrannosaurus rex User:Postdlf/images Categories: GFDL images ... Closeup of arm of Tyrannosaurus rex fossil at the National Museum of Natural History, Washington, DC; digital photo by User:Postdlf, 2/20/05 File links The following pages link to this file: Tyrannosaurus rex User:Postdlf/images Categories: GFDL images ... The museum as seen from the National Mall, the Old Post Office Building visible in the distance National Mall museum entrance The National Museum of Natural History is a museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C. The museums collections total over... Aerial photo (looking NW) of the Washington Monument and the White House in Washington, DC. Washington, D.C., officially the District of Columbia (also known as D.C.; Washington; the Nations Capital; the District; and, historically, the Federal City) is the capital city and administrative district of the United... The humerus is a long bone in the arm or fore-legs (animals) that runs from the shoulder to the elbow. ... Species type (Marsh, 1878) Paul, 1987 Mateus , 2006 jimmadseni Chure, 2000 vide Glut, 2003 Synonyms Creosaurus Marsh, 1878 Labrosaurus Marsh, 1879 Camptonotus Marsh, 1879  ?Antrodemus Leidy, 1870  ?Epanterias Cope, 1878  ?Saurophaganax Chure, 1995 Allosaurus (IPA: ) was a large bipedal carnivorous dinosaur up to 12 m (39 ft) long. ... Lawrence Morris Lambe (1849-1934) was a famous geologist and palaeontologist from the Geological Survey of Canada (GSC). ... Binomial name Gorgosaurus libratus Lambe, 1914 Gorgosaurus (Latin for dragon lizard) is a genus of carnivorous dinosaur that reached 7 to 8 meters (27 to 30 feet) in length, and weighed 2. ... A hypothesis (from Greek ) is a suggested explanation of a phenomenon or reasoned proposal suggesting a possible correlation between multiple phenomena. ... A vestigial organ is an organ whose original function is considered to have been lost or reduced during evolution. ... It has been suggested that this article or section be merged into Muscular system. ... A pair of lions copulating in the Maasai Mara, Kenya. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Grays Anatomy illustration of a human femur. ... A person flexing his biceps brachii In human anatomy, the biceps brachii is a muscle on the upper arm that acts to flex the elbow. ... Brachialis is a flexor muscle in the upper arm. ... Binomial name Deinonychus antirrhopus Ostrom, 1969 Deinonychus (IPA ) meaning terrible claw (Greek δεινος meaning terrible and ονυξ/ονυχος meaning claw) was a jaguar-sized, carnivorous dromaeosaurid dinosaur species from the Early Cretaceous Period. ...


Feathers

Main article: Feathered dinosaurs

In 2004, the scientific journal Nature published a report describing an early tyrannosauroid, Dilong paradoxus, from the famous Yixian Formation of China. As with many other theropods discovered in the Yixian, the fossil skeleton was preserved with a coat of filamentous structures which are commonly recognized as the precursors of feathers. It has also been proposed that Tyrannosaurus and other closely-related tyrannosaurids had such protofeathers. However, rare skin impressions from adult tyrannosaurids in Canada and Mongolia show pebbly scales typical of other dinosaurs. While it is possible that protofeathers existed on parts of the body which have not been preserved, a lack of body covering is consistent with modern multi-ton animals such as elephants, hippopotamus, and most species of rhinoceros, all of which lack hair over most of their bodies. As animals increase in size, their ability to retain heat increases due to their decreasing surface area-to-volume ratios. Therefore, as large animals evolve in or disperse into warm climates, a coat of fur or feathers loses its selective advantage for thermal insulation and can instead become a disadvantage, as the insulation traps excess heat inside the body, possibly overheating the animal. Protofeathers may also have been secondarily lost during the evolution of large tyrannosaurids like Tyrannosaurus, especially in warm Cretaceous climates.[40] Some scientists speculate that young tyrannosaurs may have had a feathery down, similar to modern bird chicks, but this is purely guesswork. Sinornithosaurus by Jim Robins Feathered dinosaurs are regarded by many paleontologists as transitional fossils between birds and dinosaurs (see Dinosaur-bird connection). ... First title page, November 4, 1869 Nature is one of the oldest and most reputable scientific journals, first published on 4 November 1869. ... Dilong paradoxus was an ancestor of Tyrannosaurus rex and had a covering of feathers. ... The Yixian Formation is a geological formation in Liaoning, Peoples Republic of China, that stems from the early Cretaceous period. ... Two feathers Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds. ... Genera and Species Loxodonta Loxodonta cyclotis Loxodonta africana Elephas Elephas maximus Proboscidea is an order including only one extant family, Elephantidae or the elephants, with three species: the Savannah Elephant and Forest Elephant (which were collectively known as the African Elephant), and the Asian Elephant (formerly known as the Indian... Binomial name Hippopotamus amphibius Linnaeus, 1758 The Hippopotamus (Hippopotamus amphibius), from the Greek ‘ιπποπόταμος (hippopotamos, hippos meaning horse and potamos meaning river), is a large, plant-eating African mammal, one of only two extant, and three or four recently extinct, species in the family Hippopotamidae. ... Genera Ceratotherium Dicerorhinus Diceros Rhinoceros Coelodonta (extinct) Elasmotherium (extinct) Height Comparison of Extant Rhinoceros Species. ... This article explains the meaning of area as a Physical quantity. ... Volume is how much space a thing has. ... This article is about evolution in biology. ... Biological dispersal refers to those processes by which a species maintains or expands the distribution of a population. ... The Galápagos Islands hold 13 species of finches that are closely related and differ most markedly in the shape of their beaks. ... The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer. ... Chick could refer to any of these : chick – the young of any bird, used especially for chicken chick – slang for a young girl Chick Publications – publishing company run by Jack Chick Chick flick – slang for a movie made for women Chick pea – an edible pulse...


Tyrannosaurus warm-blooded?

Main article: Warm-bloodedness of dinosaurs

Tyrannosaurus has been at the centre of the warm-blooded versus cold-blooded debate ever since its beginnings with the paleontologist Robert T. Bakker. Like many other theropods, Tyrannosaurus is thought to have been warm-blooded due to its heightened levels of activity. To have been able to capture prey actively for example, it would have been useful to the creature to be warm-blooded. T. rex also has anatomical features distinctly similar to birds, which are warm-blooded. However, since the birth of the theory that Tyrannosaurus was in fact a scavenger, the theory that Tyrannosaurus was warm-blooded has been cast into doubt. Although Bakker provided some important factual evidence, paleontologists are still divided on the issue.[41][42] Note: in this article dinosaur means non-avian dinosaur, since some experts regard birds as a specialised group of dinosaurs. ... A warm-blooded (homeothermic) animal is one that can keep its core body temperature at a nearly constant level regardless of the temperature of the surrounding environment (that is, to maintain thermal homeostasis) . This can involve not only the ability to generate heat, but also the ability to cool down... This article needs to be cleaned up to conform to a higher standard of quality. ... Robert T. Bakker Dr. Robert T. Bakker (Bob Bakker), born March 24, 1945, in Bergen County, New Jersey, is an American paleontologist who has helped re-shape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were homeothermic (warm-blooded). ... For other meanings of bird, see bird (disambiguation). ...


Feeding strategies

Tyrannosaurus rex skull and upper vertebral column, Palais de la Découverte, Paris
Tyrannosaurus rex skull and upper vertebral column, Palais de la Découverte, Paris

Most debate about Tyrannosaurus centers on its feeding patterns and locomotion. One paleontologist, noted hadrosaur expert Jack Horner, claims that Tyrannosaurus was exclusively a scavenger and did not engage in active hunting at all.[37] Horner has only presented this in an official scientific context once, while mainly discussing it in his books and in the media. His hypothesis is based on the following: Tyrannosaurs have large olfactory bulbs and olfactory nerves (relative to their brain size). These suggest a highly developed sense of smell, allegedly used to sniff out carcasses over great distances. Tyrannosaur teeth could crush bone, a skill perhaps used to extract as much food (bone marrow) as possible from carcass remnants, usually the least nutritious parts. Since at least some of Tyrannosaurus's prey could move quickly, evidence that it walked instead of ran could indicate that it was a scavenger.[43][44] Image File history File linksMetadata Download high-resolution version (2400x1552, 1409 KB) Tyrannosaurus rex, Palais de la Découverte, Paris Copyright © 2005 David Monniaux File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Dinosaur Tyrannosaurus List of dinosaurs Talk... Image File history File linksMetadata Download high-resolution version (2400x1552, 1409 KB) Tyrannosaurus rex, Palais de la Découverte, Paris Copyright © 2005 David Monniaux File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Dinosaur Tyrannosaurus List of dinosaurs Talk... Binomial name Tyrannosaurus rex Osborn, 1905 Tyrannosaurus rex (ty-RAN-o-sawr-us) meaning king tyrant lizard because of its size and large teeth and claws (Greek tyrannos = tyrant + sauros = lizard; Latin rex = king), also known colloquially as T. rex and The King of the Dinosaurs, was a giant carnivorous... Hadrosaurus foulkii is a hadrosaurid dinosaur species, and the first full dinosaur skeleton found in North America. ... John Jack R. Horner (born June 15, 1946) is an American paleontologist who discovered and named the Maiasaura, providing the first clear evidence that dinosaurs cared for their young. ... Vesalius Fabrica, 1543. ... The olfactory nerve is the first of twelve cranial nerves. ... Grays Anatomy illustration of cells in bone marrow. ...


Most scientists who have published on the subject since insist that Tyrannosaurus was both a predator and a scavenger, taking whatever meat it could acquire depending on the opportunity that was presented.[45] Modern carnivores such as lions and hyenas will often scavenge what other predators have killed, suggesting that tyrannosaurs may also have done so.[46] Binomial name Panthera leo (Linnaeus, 1758) Synonyms Felis leo (Linnaeus, 1758) The lion (Panthera leo) is a mammal of the family Felidae and one of four big cats in the genus Panthera. ... Genera Crocuta Hyaena Parahyaena Proteles Hyenas or Hyænas are moderately large terrestrial carnivores native to Africa and the Indian Subcontinent. ...


Some other evidence exists that suggests hunting behavior in Tyrannosaurus. The ocular cavities of tyrannosaurs are positioned so that the eyes would point forward, giving the dinosaur binocular vision.[47] A scavenger might not need the advanced depth perception that stereoscopic vision affords; in modern animals, binocular vision is found primarily in predators. Binocular vision is vision in which both eyes are used synchronously to produce a single image. ... Binocular vision (also referred to as stereoscopic vision) is a type of visual system common in many kinds of animals where both the eyes produce only a single image in the brain. ...

T. rex right hind foot (medial view) Oxford University Museum of Natural History

When examining Sue, paleontologist Pete Larson found a broken and healed fibula and tail vertebrae, scarred facial bones and a tooth from another Tyrannosaurus embedded in a neck vertebra. If correct, it might be strong evidence for aggressive behavior between tyrannosaurs but whether it would be competition for food and mates or active cannibalism is unclear.[48] However, further recent investigation of these purported wounds has shown that most are infections rather than injuries (or simply damage to the fossil after death) and the few injuries are too general to be indicative of intraspecific conflict.[49] In the Sue excavation site, an Edmontosaurus annectens skeleton was also found with healed tyrannosaur-inflicted scars on its tail. The fact that the scars seem to have healed suggests active predation instead of scavenging a previous kill.[50][51] Another piece of evidence is a Triceratops found with bite marks on its ilium. Again, these were inflicted by a tyrannosaur and they too appear healed.[52] Image File history File linksMetadata Download high resolution version (2560x1920, 2446 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high resolution version (2560x1920, 2446 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... The Oxford University Museum of Natural History, sometimes known simply as the Oxford University Museum, is a museum displaying many of the University of Oxfords natural history specimens. ... This article or section seems not to be written in the formal tone expected of an encyclopedia entry. ... For other uses see fibula (disambiguation) The fibula or calf bone is a bone placed on the lateral side of the tibia, with which it is connected above and below. ... Cannibalism in Brazil in 1557 as alleged by Hans Staden. ... Species Edmontosaurus (ed-MON-toh-sawr-us) meaning Edmontons lizard (Greek sauros = lizard) was a hadrosaurid dinosaur genus from the Maastrichtian, the last stage of the Cretaceous period, 71-65 million years ago. ... Species See text. ... The ilium of the pelvis is divisible into two parts, the body and the ala; the separation is indicated on the internal surface by a curved line, the arcuate line, and on the external surface by the margin of the acetabulum. ...


There have been conflicting studies regarding the extent to which Tyrannosaurus could run and exactly how fast it might have been; speculation has suggested speeds up to 70 km/h (45 mph) or even more. However, according to James Farlow, a palaeontologist at Indiana-Purdue University in Fort Wayne, Indiana, "If T. rex had been moving fast and tripped, it would have died." [53] If it tripped and fell while running, a tumbling tyrannosaur's torso would have slammed into the ground at a deceleration of 6g (six times the acceleration due to gravity, or about 60 m/s²). [54] See Locomotion, below. James Farlow is a vertebrate paleontologist, specialising on dinosaur trace fossils, biomechanics and physiology. ... Not to be confused with ipfw, Internet Protocol Firewall. ... Fort Wayne was the name of at least two historic forts in the United States of America; one of these gave its name to Fort Wayne, Indiana. ... Official language(s) English Capital Indianapolis Largest city Indianapolis Area  Ranked 38th  - Total 36,418 sq mi (94,321 km²)  - Width 140 miles (225 km)  - Length 270 miles (435 km)  - % water 1. ... Binomial name Tyrannosaurus rex Osborn, 1905 Synonyms Manospondylus gigas Dynamosaurus imperiosus Dinotyrannus megagracilis Nanotyrannus lancensis? Tyrannosaurus (IPA pronunciation or ; from the Greek τυραννόσαυρος, meaning tyrant lizard) is a genus of tyrannosaurid theropod dinosaur. ...


Some argue that if Tyrannosaurus were a scavenger, another dinosaur had to be the top predator in the Amerasian Upper Cretaceous. Top prey were the larger marginocephalians and ornithopods. The other tyrannosaurids share so many characteristics that only small dromaeosaurs remain as feasible top predators. In this light, scavenger hypothesis adherents have suggested that the size and power of tyrannosaurs allowed them to steal kills from smaller predators.[44] Suborders Pachycephalosauria Ceratopia Marginocephalia is a group of ornithischian dinosaurs that includes the thick-skulled pachycephalosaurids, and horned ceratopsians. ... Clades ?Heterodontosauridae Hypsilophodontia Iguanodontia    Hadrosauridae Ornithopods (or-nith-oh-PODS) are a group of ornithischian dinosaurs who started out as small, cursorial grazers, and grew in size and numbers until they became one of the most successful Cretaceous herbivores in the world, and totally dominated the North American landscape. ... Genera Achillobator Adasaurus Atrociraptor Bambiraptor Buitreraptor Dromaeosauroides Dromaeosaurus Deinonychus Neuquenraptor Pyroraptor Saurornitholestes Unenlagia Utahraptor Variraptor Velociraptor Dromaeosaurids, raptors or members of the family Dromaeosauridae (running lizards) are theropod dinosaurs. ... Kleptoparasitism (literally, parasitism by theft) is a form of feeding where one animal takes prey from another that has caught, killed, or otherwise prepared it. ...


Locomotion

T. rex right hind foot (lateral) Oxford University Museum of Natural History

Scientists who think that Tyrannosaurus was able to run slowly point out that hollow Tyrannosaur bones and other features that would have lightened its body may have kept adult weight to a mere 5 tons or so, or that other animals like ostriches and horses with long, flexible legs are able to achieve high speeds through slower but longer strides. Additionally, some have argued that Tyrannosaurus had relatively larger leg muscles than any animal alive today, which could have enabled fast running (40–70 km/h or 25–45 mph).[55] Image File history File linksMetadata Download high resolution version (1920x2560, 2431 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high resolution version (1920x2560, 2431 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... The Oxford University Museum of Natural History, sometimes known simply as the Oxford University Museum, is a museum displaying many of the University of Oxfords natural history specimens. ...


Some old studies of leg anatomy and living animals suggested that Tyrannosaurus could not run at all and merely walked. The ratio of femur (thigh bone) to tibia (shank bone) length (greater than 1, as in most large theropods) could indicate that Tyrannosaurus was a specialized walker, like a modern elephant. In addition, it had tiny 'arms' that could not have stopped the dinosaur's fall, had it stumbled while running; standard estimates of Tyrannosaurus weight at 6 to 8 tons would produce a lethal impact force, should it have fallen.[56] It should be noted, however, that giraffes have been known to gallop at 50 km/h (31 mph).[57] At those speeds, the animal risks breaking a leg or worse, which can be fatal even when the accident occurs in a 'safe' environment, such as a zoo.[58] If it could run, Tyrannosaurus may have been a risk-taker, in much the same way as animals alive today are. Yet estimates of leg bone strength in Tyrannosaurus show that its legs were little, if any stronger, than those of elephants, which are relatively limited in their top speed and do not ever become 'airborne', as would happen in running. Genera and Species Loxodonta Loxodonta cyclotis Loxodonta africana Elephas Elephas maximus Elephas antiquus † Elephas beyeri † Elephas celebensis † Elephas cypriotes † Elephas ekorensis † Elephas falconeri † Elephas iolensis † Elephas planifrons † Elephas platycephalus † Elephas recki † Stegodon † Mammuthus † Elephantidae (the elephants) is a family of pachyderm, and the only remaining family in the order Proboscidea... Binomial name Giraffa camelopardalis Linnaeus, 1758 The Giraffe (Giraffa camelopardalis) is an African even-toed ungulate mammal, the tallest of all land-living animal species. ...


Walking proponents estimate the top speed of Tyrannosaurus at about 17 km/h (11 mph). This is still faster than the most likely prey species that co-existed with tyrannosaurs; the hadrosaurs and ceratopsians.[59] In addition, some predation advocates claim that tyrannosaur running speed is not important, since it may have been slow but better designed for speed than its probable prey[60] or it may have used ambush tactics to attack faster prey animals.[55]

The most recent research on Tyrannosaurus locomotion does not specify how fast Tyrannosaurus may have run, but admits that there is little capacity to narrow down speeds further than a range from 17 km/h (11 mph), which would be only walking or slow running, to 40 km/h (25 mph), which would be moderate-speed running. For example, a paper in Nature[59] used a mathematical model (validated by applying it to two living animals, alligators and chickens) to gauge the leg muscle mass needed for fast running (over 25 mph / 40 km/h). They found that proposed top speeds in excess of 40 km/h (25 mph) were unfeasible, because they would require very large leg muscles (more than approximately 40–86% of total body mass.)[61] Even moderately fast speeds would have required large leg muscles. This discussion is difficult to resolve, as it is unknown how large the leg muscles were. If they were smaller, only ~11 mph (18 km/h) walking/jogging might have been possible.[55] Image File history File linksMetadata Download high resolution version (1920x2560, 2780 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high resolution version (1920x2560, 2780 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... The Oxford University Museum of Natural History, sometimes known simply as the Oxford University Museum, is a museum displaying many of the University of Oxfords natural history specimens. ... First title page, November 4, 1869 Nature is one of the oldest and most reputable scientific journals, first published on 4 November 1869. ...


History

Henry Fairfield Osborn, president of the American Museum of Natural History, named Tyrannosaurus rex in 1905. The generic name is derived from the Greek words τυραννος (tyrannos, meaning "tyrant") and σαυρος (sauros, meaning "lizard"). Osborn used the Latin word rex, meaning "king", for the specific name. The full binomial therefore translates to "tyrant lizard king," emphasizing the animal's size and perceived dominance over other species of the time.[35] Henry Fairfield Osborn (August 8, 1857 — November 6, 1935) was an American paleontologist and geologist. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... Latin was the language originally spoken in the region around Rome called Latium. ... In biology, binomial nomenclature is the formal method of naming species. ...


Earliest finds

The vertebrae named Manospondylus by Cope in 1892 can be considered the first known specimen of Tyrannosaurus rex. Barnum Brown, assistant curator of the American Museum of Natural History, found the second Tyrannosaurus skeleton in Wyoming in 1900. This specimen was originally named Dynamosaurus imperiosus in the same paper in which Tyrannosaurus rex was described.[62] Had it not been for page order, Dynamosaurus would have become the official name. The original "Dynamosaurus" material resides in the collections of the Natural History Museum, London.[63] Barnum Brown (1873-1963) was perhaps the most famous fossil hunter of the early Twentieth Century. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... Official language(s) English Capital Cheyenne Largest city Cheyenne Area  Ranked 10th  - Total 97,818 sq mi (253,348 km²)  - Width 280 miles (450 km)  - Length 360 miles (580 km)  - % water 0. ... For other similarly-named museums see Museum of Natural History. ... This article is about the capital of England and the United Kingdom. ...

Scale model of the never-completed Tyrannosaurus rex exhibit planned for the American Museum of Natural History by H.F. Osborn
Scale model of the never-completed Tyrannosaurus rex exhibit planned for the American Museum of Natural History by H.F. Osborn

In total, Barnum Brown found five Tyrannosaurus partial skeletons. Brown collected his second Tyrannosaurus in 1902 and 1905 in Hell Creek, Montana. This is the holotype used to describe Tyrannosaurus rex Osborn, 1905. In 1941 it was sold to the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. Brown's fourth and largest find, also from Hell Creek, is on display in the American Museum of Natural History in New York.[37] Image File history File links AMNH_rex_mount. ... Image File history File links AMNH_rex_mount. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... Henry Fairfield Osborn (August 8, 1857 — November 6, 1935) was an American paleontologist and geologist. ... The Hell Creek Formation is the division of Upper Cretaceous rocks in North America. ... This article or section does not cite its references or sources. ... A holotype is one of several possible types. ... Henry Fairfield Osborn (August 8, 1857 — November 6, 1935) was an American paleontologist and geologist. ... The Carnegie Museums of Pittsburgh are operated by the Carnegie Institute and located in Pittsburgh, Pennsylvania. ... Nickname: Steel City, Iron City, City of Champions, City of Bridges, City of Colleges Location in Allegheny County, Pennsylvania Coordinates: Country United States State Pennsylvania County Allegheny County Founded 1758 Mayor Luke Ravenstahl (D) Area    - City 151. ... This article is about the U.S. State. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... NY redirects here. ...


Named skeletons

Another Tyrannosaurus, nicknamed "Stan", in honor of amateur paleontologist Stan Sacrison, was found in the Hell Creek Formation near Buffalo, South Dakota, in the spring of 1987. After 30,000 hours of digging and preparing, a 65% complete skeleton emerged. Stan is currently on display in the Black Hills Museum of Natural History Exhibit in Hill City, South Dakota, after an extensive world tour. This tyrannosaur, too, was found to have many bone pathologies, including broken and healed ribs, a broken (and healed) neck and a spectacular hole in the back of its head, about the size of a Tyrannosaurus tooth. Both Stan and Sue were examined by Peter Larson. Buffalo is a town located in Harding County, South Dakota. ... Hill City is a city located in Pennington County, South Dakota. ...

Sue the Tyrannosaurus, Field Museum of Natural History, Chicago, showing the forelimbs. The 'wishbone' is between the forelimbs.
Sue the Tyrannosaurus, Field Museum of Natural History, Chicago, showing the forelimbs. The 'wishbone' is between the forelimbs.

Susan Hendrickson, amateur paleontologist, discovered the most complete (more than 90%) and, until 2001 the largest, Tyrannosaurus fossil skeleton known in the Hell Creek Formation near Faith, South Dakota, on August 12, 1990. This Tyrannosaurus, now named "Sue" in her honor, was the object of a legal battle over its ownership. In 1997 this was settled in favor of Maurice Williams, the original land owner, and the fossil collection was sold at auction for USD 7.6 million. It has now been reassembled and is currently exhibited at the Field Museum of Natural History. Based on a study of 'her' fossilized bones, Sue died at 28 years of age, having reached full size at 19 years of age. Researchers report that a subadult and a juvenile skeleton were found in the same quarry as Sue; this lends evidence to the possibility that tyrannosaurs ran in packs or other groups.[64] Image File history File links Field_fg05. ... Image File history File links Field_fg05. ... Field Museum of Natural History, Chicago The Field Museum of Natural History, in Chicago, Illinois, USA, sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex known as Museum Campus Chicago. ... Look up amateur in Wiktionary, the free dictionary. ... The Hell Creek Formation is the division of Upper Cretaceous rocks in North America. ... Faith is a city in Meade County, South Dakota, United States. ... August 12 is the 224th day of the year (225th in leap years) in the Gregorian Calendar. ... This article is about the year. ... The United States dollar is the official currency of the United States. ... Field Museum of Natural History, Chicago The Field Museum of Natural History, in Chicago, Illinois, USA, sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex known as Museum Campus Chicago. ...


In 2001, a 50% complete skeleton of a juvenile Tyrannosaurus was discovered in the Hell Creek Formation in Montana, by a crew from the Burpee Museum of Natural History of Rockford, Illinois. Dubbed "Jane the Rockford T-Rex," the find was initially considered the first known skeleton of the pygmy tyrannosaurid Nanotyrannus but subsequent research has revealed that it is more likely a juvenile Tyrannosaurus.[65] It is the most complete and best preserved juvenile example known to date. Jane has been examined by Jack Horner, Pete Larson, Robert Bakker, Greg Erickson and several other renowned paleontologists, because of the uniqueness of her age. Jane is currently on exhibit at the Burpee Museum of Natural History in Rockford, Illinois.[66][67] Burpee Museum of Natural History The Burpee Museum of Natural History is located along the Rock River in downtown Rockford, Illinois at 737 North Main Street. ... Rockford is the name of several places in the United States of America: Rockford, Alabama Rockford, Illinois Rockford, Iowa Rockford, Michigan Rockford, Minnesota Rockford Township, Minnesota Rockford, Ohio Rockford, Tennessee Rockford, Washington Rockford is also the name used by Mastertronic/Arcadia Systems for their licensed versions of the computer game... Official language(s) English Capital Springfield Largest city Chicago Area  Ranked 25th  - Total 57,918 sq mi (149,998 km²)  - Width 210 miles (340 km)  - Length 390 miles (629 km)  - % water 4. ... Jane is a renowned juvenile Tyrannosaurus Rex fossil discovered in the Hell Creek Formation in southern Montana. ... Binomial name Nanotyrannus lancensis Bakker, Currie & Williams, 1988 Nanotyrannus (tiny tyrant) was erected in 1988 for a small tyrannosaurid skull, previously described in 1946 (Gilmore) as Albertosaurus lancensis. ... John Jack R. Horner (born June 15, 1946) is an American paleontologist who discovered and named the Maiasaura, providing the first clear evidence that dinosaurs cared for their young. ... This article or section seems not to be written in the formal tone expected of an encyclopedia entry. ... Robert T. Bakker (Bob Bakker), born in Bergen, New Jersey, 1945, is a famous American paleontologist who has helped re-shape modern theories about dinosaurs, particularly by adding support to the theory that some dinosaurs were homeothermic (warm-blooded). ... A paleontologist carefully chips rock from a column of dinosaur vertebrae. ...


Also in 2001, Dr. Jack Horner discovered a specimen of T. rex around 10% larger than "Sue". Dubbed C. rex (or "Celeste" after Jack's wife), this specimen is currently under study.


Latest news

In the March 2005 Science magazine, Mary Higby Schweitzer of North Carolina State University and colleagues announced the recovery of soft tissue from the marrow cavity of a fossilized leg bone, from a 68 million-year-old Tyrannosaurus. The bone had been intentionally, though reluctantly, broken for shipping and then not preserved in the normal manner, specifically because Schweitzer was hoping to test it for soft tissue. Designated as the Museum of the Rockies specimen 1125, or MOR 1125, the dinosaur was previously excavated from the Hell Creek Formation. Flexible, bifurcating blood vessels and fibrous but elastic bone matrix tissue were recognized. In addition, microstructures resembling blood cells were found inside the matrix and vessels. The structures bear resemblance to ostrich blood cells and vessels. Whether an unknown process, distinct from normal fossilization, preserved the material, or the material is original, the researchers do not know, and they are careful not to make any claims about preservation.[68] If it is found to be original material, any surviving proteins may be used as a means of indirectly guessing some of the DNA content of the dinosaurs involved, because each protein is typically created by a specific gene. The absence of previous finds may merely be the result of people assuming preserved tissue was impossible, therefore simply not looking. Since the first, two more tyrannosaurs and a hadrosaur have also been found to have such tissue-like structures.[69][70] Science is the journal of the American Association for the Advancement of Science (AAAS). ... North Carolina State University is a public, coeducational, extensive research university located in Raleigh, North Carolina, United States. ... The arterial system The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... Grays Anatomy illustration of a human femur. ... A blood cell is any cell of any type normally found in blood. ... Binomial name Struthio camelus Linnaeus, 1758 The present-day distribution of ostriches. ...


In a press release on April 7, 2006, Montana State University revealed that it possessed the largest Tyrannosaurus skull yet discovered. Discovered in the 1960s and only recently reconstructed, the skull measures 59 inches (150 cm) long compared to the 55.4 inches (141 cm) of “Sue’s” skull, a difference of 6.5%.[71][72] April 7 is the 97th day of the year in the Gregorian calendar (98th in leap years). ... 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...


Appearances in popular culture

Since it was first described in 1905, Tyrannosaurus has become the most widely-recognized dinosaur in popular culture. It is the only dinosaur which is commonly referred to by its scientific name, Tyrannosaurus rex, among the general public, and the scientific abbreviation T. rex (often mistakenly spelled "T-Rex") has also come into wide usage.[1] Museum exhibits featuring T. rex are very popular; an estimated 10,000 visitors flocked to Chicago's Field Museum on the opening day of its "Sue" exhibit in 2003.[73] T. rex has appeared numerous times on television and in films, notably The Lost World, King Kong, Jurassic Park, and specifically in The Land Before Time, (as the Sharptooth). A number of books and comic strips, including Calvin and Hobbes, have also featured Tyrannosaurus, which is typically portrayed as the biggest and most terrifying carnivore of all (with the exception of Dinosaurs where the character Roy is portrayed as dim-witted and barely able to chew a lunch that's already accepted its fate as food). At least one musical group, the band T. Rex, is named after the species, as is The Hives' third album, Tyrannosaurus Hives. Tyrannosaurus-related toys, video games, and other merchandise remain popular. Various businesses have capitalized on the popularity of Tyrannosaurus rex by using it in advertisements. A CGI breaks free from its enclosure in the highly acclaimed 1993 Steven Spielberg film Jurassic Park. ... Popular culture, or pop culture, (literally: the culture of the people) consists of widespread cultural elements in any given society. ... Film is a term that encompasses motion pictures as individual projects, as well as the field in general. ... The Lost World is a 1912 novel by Arthur Conan Doyle concerning an expedition to a plateau in South America where prehistoric animals (dinosaurs and other extinct creatures) still survive. ... Peter Jacksons King Kong is a multiplatform videogame based on the forthcoming movie King Kong. ... Jurassic Park is a 1993 film directed by Steven Spielberg, based off the novel written by Michael Crichton. ... The Land Before Time is an animated film, produced by Steven Spielbergs Amblin Entertainment, and directed by Don Bluth. ... The original Sharptooth faces off against Littlefoots mother. ... This article is about the comic strip, the sequential art form as published in newspapers and on the Internet. ... Listen to this article (3 parts) · (info) Part 1 · Part 2 · Part 3 This audio file was created from an article revision dated 2006-01-29, and may not reflect subsequent edits to the article. ... Dinosaurs was an American television sitcom on ABC, produced by Michael Jacobs Productions and Jim Henson Productions in association with Walt Disney Television and Sunbow Productions about a family of talking dinosaurs that ran for 65 episodes from April 1991 to July 1994. ... T. Rex (originally known as Tyrannosaurus Rex, also occasionally spelled T Rex or T-Rex), were an English rock band fronted by Marc Bolan. ... The Hives is a rock band from Fagersta, Sweden that first rose to prominence in the early 2000s as a leading group of the garage rock revival. ... Tyrannosaurus Hives is the third full-length The Hives. ... A teddy bear A toy is an object meant to be played with. ... Namcos Pac-Man was a hit, and became a cultural phenomenon. ... Wikibooks has more about this subject: Marketing Billboards and street advertising in Shinjuku, Tokyo, Japan, (2005) Advertising is paid communication through a non-personal medium in which the sponsor is identified and the message is controlled. ...


Footnotes

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  53. ^ "The bigger they come, the harder they fall" New Scientist, October 7, 1995, p. 18.
  54. ^ http://www.answersingenesis.org/creation/v18/i2/dinosaurs.asp "The bigger they are ..." Creation Magazine, Vol 18, Issue 2, pg52, pub. March 1996
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  67. ^ Visit Jane.com. Official musuem website.
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References

  • Erickson, G. M., Van Kirk, S. D., Su, J., Levenston, M. E., Caler, W. E., and Carter, D. R. (1996). "Bite-force estimation for Tyrannosaurus rex from tooth-marked bones.". Nature 382: 706-708.
  • Meers, Mason B. (August 2003). "Maximum Bite Force and Prey Size of Tyrannosaurus rex and Their Relationships to the Inference of Feeding Behavior". Historical Biology: A Journal of Paleobiology 16 (1): 1 - 12. DOI:10.1080/0891296021000050755.
  • Schweitzer, Mary H.; Wittmeyer, Jennifer L.; Horner, John R.; Toporski, Jan K. (25 March 2005). "Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex". Science 307 (5717): 1952–1955. DOI:10.1126/science.1108397.

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External links

Wikimedia Commons has media related to:
Tyrannosaurus
Wikibooks
Wikibooks has a book on the topic of
Wikijunior Dinosaurs/T-Rex
  • "The secret of T. rex's colossal size: a teenage growth spurt", The Guardian, August 12, 2004.
  • Sue's homepage
  • Stan's homepage
  • Pictures of a replica of Sue the T. rex
  • History of the first T. rex finds
  • Tree of Life discussing Tyrannosauridae
  • Unearthing Tyrannosaurus rex
  • T.rex juvenile Jane
  • Cretaceous Hell Creek Faunal Facies is an example of one tyrannosaur environment, in the Hell Creek Formation of Montana
  • Bristol University study on bite forces of predators
  • Museum of Unnatural Mystery - Bite force etc. of T. rex
  • University of Tampa on bite force etc. of T. rex
  • Stanford University on bite force of T. rex
  • How Tyrannosaurus might have had sex
  • Recent Discovery of Soft Tissue

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