A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Appendix

Talarurus
Taxon: Ankylosauria Ankylosauridae
Name means: “wicker tail”
Pronounced: TAL-uh-ROOR-us
Length: 13.5 – 16.5 ft (4 – 5 m)
Time: Late Cretaceous, 97.5 – 88.5 mya
Place: Mongolia (China)

This mid-sized armored dinosaur was an ankylosaurid with spikes on its sides and a defensive club at the end of its tail. Talarurus was named for the Russian term for wicker, a description of the dinosaur based on its interlocking tail vertebrae and the ossified, or stiffened, tendons which wove them together. The plant-eating, four-legged Talarurus had a long, narrow skull and was named in 1952.

Tangvayosaurus
Taxon: Sauropoda Titanosauria
Name means: “Tang Vay lizard,” for the village of Tang Vay
Pronounced: tahng-VYE-o-SAW-rus
Length: about 50 ft (15 m)
Time: Early Cretaceous, 121 – 99 mya
Place: Laos

This titanosaur from Laos was moderately large by the standards of the giant long-necked sauropod dinosaurs. Based on two partially-articulated skeletons, both missing their skulls, the plant-eating Tangvayosaurus appears to have been similar to Phuwiangosaurus, a Late Jurassic sauropod from Thailand. An early, anatomically primitive sauropod, Tangvayosaurus was named in 1999.

Tanius
Taxon: Ornithopoda Hadrosauridae, probably Hadrosaurinae
Name means: “for Tan,” after H. C. Tan, a Chinese geologist
Pronounced: TAN-ee-us
Length: Moderate
Time: Late Cretaceous, c. 88.5 - 65 mya
Place: China

This large duckbill from the Wangshi Formation in China had a low, flat skull. Since there is no evidence of a crest on its head, it may have belonged to the hadrosaurine group, a crestless branch of the hadrosaurid duckbill family. Some scientists speculate that Tanius, which was named in 1929, may be the same animal as Tsintaosaurus.

Tanystrosuchus
Name means: elongated crocodile
pronounced: TAN-stroh-SOOK-us
This dinosaur is generally considered to be HALTICOSAURUS.

Tarascosaurus
Taxon: Abelisauridae
name means: “Tarasque lizard”
pronounced: tuh-RAS-kuh-SAW-rus
Length: Moderate
time: Late Cretaceous
place: France

Named after a legendary dragon-like monster called Tarasque, said to have terrorized the town of Tarascon in southern France, this abelisaurid was a medium-sized predator with a large skull, double-edged teeth, strong hind limbs and large, talon-bearing toes. Similar theropods roamed South America, India and Africa during the Late Cretaceous, suggesting that a common ancestor made use of land bridges to spread its descendants across the continents.

Tarbosaurus
Taxon: Theropoda Tyrannosauridae
Name means: “alarming lizard”
Pronounced: TAR-bo-SAWR-us
Length: 39 – 46 ft (12 – 14 m)
Time: Late Cretaceous, 74 mya
Place: Mongolia

This large tyrannosaurid genus has proven to be a source of much paleontological perplexity, with some experts suggesting that species of Tarbosaurus actually belong to other genera. Considered for some time to be a dubious name, “Tarbosaurus” has recently seen a resurgence of support and is once again being called a distinct genus of the large-skulled, powerful-legged, short-armed, two-fingered tyrannosaurid meat-eaters. The largest species of Tarbosaurus appears to have been slightly longer from nose to tail, but slightly shorter from the ground to the top of the hips, than Tyrannosaurus rex. Debate continues over whether that species, which had a four-foot skull and teeth nearly six inches long, should be classified as Tarbosaurus bataar, Tyrannosaurus bataar, or even Jenghizkhan bataar. With the lines between genera often blurring, Tarbosaurus is an excellent example of the confusion that can arise when we attempt to distinctly classify very similar, closely-related animals.

Tarchia
Taxon: Ankylosauria Ankylosauridae
Name means: “brainy one”
Pronounced: TAR-chee-uh
Length: about 18 ft (5.5 m)
Time: Late Cretaceous, 78 – 69 mya
Place: Mongolia

This Chinese ankylosaur was named for its unusually large braincase. Tarchia is among the largest of the Asian club-tailed armored plant-eaters. It had spikes at the back of its skull behind the eyes and wielded an especially hefty bony tail-club. The genus was named in 1977.

Tatisaurus
Taxon: Thyreophora
Name means: “Dadi lizard”
Pronounced: TAT-I-SAW-rus
Length: about 3 – 6.5 ft (1 - 2 m)
Time: Early Jurassic, 208 – 188 mya
Place: China

A fragment from a left jawbone, including teeth, helped paleontologists to identify this small plant-eater from the Yunnan Province of China. Slender with simple teeth, the shape of the jaw indicates that Tatisaurus may have had mammal-like cheek pouches to keep plant material in its mouth while it chewed. When first discovered, Tatisaurus was believed to be a hypsilophodontid. It was later reclassified as a thyreophoran dinosaur, a member of the group that includes both stegosaurs and ankylosaurs.

Taveirosaurus
Taxon: Pachycephalosauria
Name means: “Taveiro lizard”
Pronounced: tuh-VYE-ruh-SAW-rus
Length: Small
Time: Late Cretaceous, 73 – 65 mya
Place: Portugal

Named in 1991 after the Portugese village of Taveiro, this plant-eating bone-headed dinosaur was described based on teeth that were similar to those of Wannanosaurus. Although the pachycephalosaurs were only medium-sized as dinosaurs go, Taveirosaurus was likely small even for a flat-headed member of that thick-skulled group.

Tawasaurus
Name means: “Dawa lizard”
Pronounced: DAH-wuh-SAW-rus

This is considered to be LUFENGOSAURUS.

Technosaurus
Taxon: Ornithischia
Name means: “Tech Lizard,” after Texas Tech University
Pronounced: TECK-nuh-SAW-rus
Length: 3 – 6.5 ft (1 – 2 m)
Time: Late Triassic, 231 – 225 mya
Place: Texas

Once considered to be the most primitive of the small bird-hipped plant-eaters, this assemblage of fossil bones appears to include some prosauropod hatchling material which obviously did not belong to the same animal. Because so little distinctive material was found, details about Technosaurus remain sketchy. The dinosaur was named in 1984 for Texas Tech University, the academic sponsor of the dig.
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Tecovasaurus
Taxon: Ornithischia
Name means: “Tecovas lizard” or “Texas lizard”
Pronounced: teck-OH-va-SAW-rus
Length: Unknown
Time: Late Triassic, 227 – 221 mya
Place: Arizona, Texas, possibly France

Hunt and Lucas named this primitive ornithischian dinosaur in 1994 based only on the discovery of its teeth. It was unearthed in the Tecovas Formation of Texas and Arizona.

Tehuelchesaurus
Taxon: Sauropoda
Name means: “Tehuelche lizard”
Pronounced: taye-WAYL-chay-SAW-rus
Length: about 50 ft (15 m)
Time: Middle Jurassic, c. 164 - 159 mya
Place: Argentina

Respectfully named for the Tehuelche, an indigenous people native to Argentina, this large, cetiosaur-like sauropod was found without its skull, but with a skeleton that was about half complete. Rare skin impressions helped paleontologists to define the long-necked, plant-eating dinosaur, which was similar to Omeisaurus but set apart by the shape and robust qualities of its limbs. Tehuelchesaurus was named in 1999.

Teinurosaurus
Taxon: possibly Theropoda
name means: “Stretched tailed lizard”
pronounced: TAYN-yoor-uh-SAW-rus
Length: Small
time: Late Jurassic
place: France

The single backbone from which this small meat-eater was described was destroyed during World War II. Paleontologists’ early notes compared it first to Iguanodon, then to Camptosaurus, both plant-eating dinosaurs. In fact, Teinurosaurus may have more closely resembled the meat-eating Elaphrosaurus.

Telmatosaurus
Taxon: Hadrosauridae
Name means: “marsh lizard”
Pronounced: tel-MAT-uh-SAW-rus
Length: 16 ft (5 m)
Time: Late Cretaceous, 83 – 65 mya
Place: Romania, France

When this plant-eating hadrosaur was described in 1903, it was thought to have been a swamp-dwelling creature. Today, such an environment is considered less likely for the duckbilled Telmatosaurus. Fossilized eggs and embryonic duckbill remains found in Transylvania may have belonged to this primitive, flat-headed hadrosaur genus.

Tenontosaurus
Taxon: Iguanodontidae
Name means: “tendon lizard”
Pronounced: te-NON-tuh-SAW-rus
Length: 23 ft (7 m)
Time: Early Cretaceous, 116 – 113 mya
Place: Montana, Wyoming, Utah, Texas, Oklahoma

This large plant-eater could probably walk both on two legs and on all fours depending on its need and the terrain. It had a skull similar to that of Iguanodon. Its long arms appear to have been strongly muscled. The dinosaur’s tail was extremely long and stiffened by hardened ossified tendons to help counterbalance its bulky body. Unfortunately for Tenontosaurus, it was likely one of the favorite meals of the sickle-clawed predator Deinonychus. Teeth from that meat-eater are often found near or mixed in with Tenontosaurus remains. Sometimes excavated in swampy Cretaceous settings along with turtles and crocodilian species, Tenontosaurus may have preferred the wetlands in life. The genus was named in 1970 by John Ostrom.

Tetragonosaurus
Name means: “four-cornered reptile”
Pronounced: tet-ra-GOHN-o-SAWR-us

This dinosaur is now considered to be LAMBEOSAURUS.

Texasetes
Taxon: Ankylosauria Nodosauridae
Name means: “Texas resident”
Pronounced: tek-sas-EE-teez
Length: 8 – 10 ft (2.5 – 3 m)
Time: Early Cretaceous, 112 – 99 mya
Place: Texas

Fragmentary fossils found in Texas indicate that Texasetes was a plant-eating nodosaur, an armored ankylosaurian with no defensive club at the end of its tail. The genus was named in 1995.

Thecodontosaurus
Taxon: Prosauropoda Thecodontosauridae
Name means: “socket tooth lizard”
Pronounced: THEE-koh-DON-tuh-SAW-rus
Length: 10 ft (3 m)
Time: Late Triassic, 225 mya
Place: England, Wales

Thecodontosaurus was a thecodontosaurid, a member of the only dinosaur family of plant-eaters known to have been entirely bipedal. Some scientists have said that its distinctive teeth resemble those of modern monitor lizard, suggesting that it may have been an omnivore, eating both plants and meat. Thecodontosaurus was named in 1836.

Thecospondylus
Name means: “socket vertebrae”
Pronounced: THEE-koh-SPON-di-lus

This dinosaur is now considered to be CALAMOSPONDYLUS.

Therizinosaurus
Taxon: Theropoda Therizinosauroidea Therizinosauridae
Name means: “reaping lizard”
Pronounced: THER-I-ZEE-nuh-SAW-rus
Length: 26 – 36 ft (8 – 11 m)
Time: Late Cretaceous, 77 – 69 mya
Place: Mongolia

Once thought to have been a sprawling, turtle-like aquatic reptile, Therizinosaurus is, in fact, a mysterious, large, bipedal dinosaur called a therizinosaur. Therizinosaurs are a great puzzle to paleontologists, bearing similarities to both meat-eating and plant-eating animals. This “reaper lizard” was named in 1954 for its enormous, scythe-like hand claws, which were a full two feet in length. It is unclear just how these claws were used. They may have been an offensive weapon or employed in defense against predators. They might have been used to rake branches, or perhaps to dig for insects in anthills or rotting tree trunks. This dinosaur’s ponderous body and large claws somewhat resemble the anatomical specializations of the extinct giant ground sloth. Perhaps this mysterious dinosaur had a similar lifestyle to that more recent mammal.

Therosaurus
Name means: “beast lizard”
Pronounced: THER-uh-SAW-rus

This dinosaur is considered to be IGUANODON.

Thescelosaurus
Taxon: Ornithopoda Hypsilophodontidae
Name means: “surprising lizard”
Pronounced: THES-ki-luh-SAW-rus
Length: about 12 ft (3.5 m)
Time: Late Cretaceous, 77 – 65 mya
Place: Alberta, Saskatchewan, Colorado, Montana, South Dakota, Wyoming

The first articulated dinosaur skeleton to be discovered, Thescelosaurus remained sealed in a crate and untouched from its excavation in 1891 until 1913. When paleontologists were finally able to study the long-lost bones, they were surprised to discover that they belonged to a previously-undescribed species of small dinosaur. The plant-eater had a small head, a stocky body, and a long tail. Its unusually short legs suggest that this particular hypsilophodontid may have been more prone to walking on all fours than were its more long-limbed relatives.

Tianchisaurus (Tianchiasaurus)
Taxon: Ankylosauria Ankylosauridae
Name means: “Heavenly Pool lizard”
Pronounced: tee-AN-chee-SAWR-us (or TYEN-CHUHR-a-SAWR-us ?)
Length: 10 ft (3 m)
Time: Middle to Late Jurassic, 169 – 164 mya
Place: China

This armored ankylosaur was originally referred to informally as “Jurassosaurus,” in honor of the film “Jurassic Park.” The club-tailed dinosaur’s species name, “nedegoapeferima,” is formed from the first two letters of the last names of most of the movie cast.
TIANCHIASAURUS (TYEN-CHUHR-a-SAW-rus)
Formerly “JURASSOSAURUS”

Tianzhenosaurus
Taxon: Ankylosauria Ankylosauridae
Name means: “Tianzhen lizard”
Pronounced: TYEN-juhn-o-SAW-rus
Length: about 10 ft (3 m)
Time: Late Cretaceous, c. 90 – 65 mya
Place: China

Known from a nearly-complete fossilized skull, this small armored ankylosaur had two horns that protruded out and backwards from the roof of the skull at the back of its head. The length of its snout and the shape of the nostrils differ from Saichania and Pinacosaurus, two other club-tailed ankylosaurids found in the region. Protective bony knobs of irregular sizes covered the top of this dinosaur’s head in life. Tianzhenosaurus was named in 1998.

Tienshanosaurus
Taxon: Sauropoda
Name means: “Heavenly Mountains lizard”
Pronounced: TEE-an-SHAN-uh-SAW-rus
Length: 33 – 39 ft (10 – 12 m)
Time: Late Jurassic, 163 – 156 mya
Place: China

Found in a mountainous region of northwestern China, this primitive long-necked dinosaur appears to have been a member of the titanosaur family of sauropods. Unusually short limbs set Tienshanosaurus apart from otherwise similar plant-eating browsers. It had a sloping head and peglike teeth. Although some titanosaurs are known to have been protected by bony plates of armor, none has been found in association with Tienshanosaurus at this time. The genus was named in 1937.

Timimus
Taxon: Theropoda, probably Ornithomimosauria Ornithomimidae
Name means: “Tim’s mimic”
Tim’s ornithomimid
Pronounced: ti-MIEM-us
Length: 10 ft (3 m)
Time: Early Cretaceous, 112 – 99 mya
Place: Australia

Named in 1994 to honor both Timothy Rich, the son of the fossil hunter who discovered the theropod, and Timothy Flannery, an associate, Timimus is known only from a single slender leg bone. Although this dinosaur is generally classified as a member of the ostrich-like ornithomimosaur sprinters, some scientists believe that it was actually a coelurosaur.

Titanosaurus
Taxon: Sauropoda Titanosauridae
Name means: “Titan lizard”
Pronounced: tye-TAN-uh-SAW-rus
Length: 60 – 66 ft (18 – 20 m)
Time: Late Cretaceous, 83 – 65 mya
Place: India, Argentina, England
Date: 1877

This four-legged sauropod, named in 1877, was described based on two vertebrae discovered in India. Titanosaurus was a plant-eating browser with a sloping head. Cannonball-shaped dinosaur eggs which were also found in India may have belonged to Titanosaurus or a related member of the long-necked, four-legged sauropod giants.

Tomodon
Name means: “cutting tooth”
Pronounced: TOM-uh-don

This dinosaur is now known as DIPLOTOMODON.

Tornieria
Name means: “for Tornier”
Pronounced: tor-NEER-ee-a

This dinosaur is now considered to be part of BAROSAURUS.

Torosaurus
Taxon: Ceratopsia Ceratopidae
Name means: “punctured lizard” or “perforated lizard”
Pronounced: TOR-uh-SAW-rus
Length: 20 – 26 ft (6 – 8 m)
Time: Late Cretaceous, 70 – 65 mya
Place: Wyoming, Utah, South Dakota, Montana, New Mexico, Texas, Saskatchewen

This ceratopsian dinosaur had the longest-known skull of any animal ever to walk the Earth. From the tip of its parrot-like beak to the end of its bony neck frill, the head of Torosaurus stretched a full 8.5 feet long. This record is a rare distinction for a relatively rare three-horned dinosaur. The plant-eater’s frill had a huge pair of openings which lightened the massive structure but made it fairly useless as a defensive shield. These window-like spaces were the inspiration for the dinosaur’s name. Torosaurus was named in 1891.

Torvosaurus
Taxon: Theropoda Carnosauria Megalosauridae
Name means: “savage lizard”
Pronounced: TOR-voh-SAW-rus
Length: 31 ft (9.5 m)
Time: Late Jurassic, 156 – 145 mya
Place: Colorado, Wyoming

This large, robust meat-eater was a powerful predatory biped, differing from Allosaurus and many other carnivores in the structure of its forelimbs and pelvis. These distinctive features indicate that Torvosaurus may have been closely related to more primitive theropods like Megalosaurus and Erectopus. Torvosaurus was named in 1979.

Tochisaurus
Taxon: Theropoda Coelurosauria Troodontidae
Name means: “ostrich foot lizard”
Pronounced: TOH-chee-SAW-rus
Length: Small
Time: Late Cretaceous, 77 – 69 mya
Place: Mongolia

This small, meat-eating troodontid was named in 1991 for its ostrich-like metatarsus, or foot bone. This bone was slender and suggests that the dinosaur’s legs were well-suited to quick bursts of speed. Like all troodontids, Tochisaurus had a large brain and may have been a particularly cunning hunter of small prey.

Trachodon
Taxon: Ceratopsia and Hadrosauridae
name means: “rough tooth”
pronounced: TRACK-uh-don
Length: Moderate
Time: Late Cretaceous
Place: Montana

Trachodon was originally named in 1856 based on a scattering of isolated teeth, some belonging to ceratopsians. The name went on to be a kind of “catch all” genus for unidentified species of crestless duckbills. Once the fossil history was thoroughly reviewed by J.B. Hatcher in 1902, it was determined that the collection attributed to Trachodon actually belonged to more than one species. Although “Trachodon” is technically a ceratopsian, since it was likely first known from a horned dinosaur tooth, it has remained a place to file undetermined duckbilled dinosaurs until they are indentified. Severaal species from Hadrosaurus, Edmontosaurus and Anatotitan started out as members of “Trachodon.”

Triceratops
Taxon: Ceratopsia Ceratopidae
Name means: "three horned face"
Pronounced: trye-SER-uh-tops
Length: 26 – 29.5 ft (8 - 9 m)
Time: Late Cretaceous, 68 - 65 mya
Place: Wyoming, Montana, South Dakota, Colorado, Alberta, Saskatchewan

The largest and most famous ceratopsian yet discovered, Triceratops is unusual in having no window-like openings in its short, solid neck-frill of bone. Its shear-like tooth batteries were probably adapted for slicing through tough, fibrous plants, with the upper and lower teeth sliding past each other like scissor blades. A stocky four-legged dinosaur, Triceratops may have weighed as much as five tons. Some scientists believe that this and other ceratopsians lived migratory lives, perhaps traveling the plains of the Mesozoic in mighty herds. The function of the frills and horns of ceratopsians remains uncertain. The horns, often very long and pointed, may have served a role in defense against predators like Tyrannosaurus rex. One Triceratops skull even bears a partially-healed scar containing the tip of another ceratopsian’s horn, showing us that the dinosaurs likely engaged in ritual combat with one another, locking horns over potential mates, status or territory. The horn-bones of the skull were probably covered with a sheath of dense keratin, making them even longer and sharper than they appear from fossil remains. Othniel Marsh originally thought that the horns of Triceratops belonged to a prehistoric bison. The sturdy frill which fanned out from the back of the dinosaur’s skull may have been more useful as a protective shield for its neck than were the more delicate, thin-boned frills of most ceratopsians. Perhaps these broad displays were brightly colored in life, serving as ornamentation to attract a mate, to warn off predators, or to identify the species to other horned dinosaurs.

Troodon
Taxon: Theropoda Coelurosauria Troodontidae
Name means: “wounding tooth”
Pronounced: TROH-uh-don
Length: about 6 – 11.5 ft (1.75 – 3.5 m)
Time: Late Cretaceous, 76 – 70 mya
Place: Alberta, Montana, Wyoming

A lightly-built, agile theropod with a long neck, nimble fingers and birdlike legs, this small carnivore was likely an excellent hunter. An unsually large brain suggests that Troodon was among the most intelligent of dinosaurs. Although the slender predator weighed only an estimated 50 pounds, its brain accounted for almost two ounces of that mass – proportionally enormous when compared to other dinosaurs of its time. Troodon had unusually large eyes, suggesting keen eyesight and perhaps the ability to see clearly in the darkness of night. The orientation of the sockets behind the narrow, toothy snout indicates that the dinosaur may have had excellent depth perception, a vital tool for a pursuit hunter. Swift and slender, Troodon could probably chase down a meal of small reptiles or mammals with ease. The enlarged “killing claw” on the second toe of each hind foot suggests that the dinosaur may also have fed on larger, more formidable prey. Troodon was named in 1856.

Tsagantegia
Taxon: Ankylosauria Ankylosauridae
Name means: “for Tsagan Teg”
Pronounced: tsah-gahn-TAY-gee-a
Length: Moderate
Time: Late Cretaceous, c. 99 – 65 mya
Place: Mongolia

Named in 1993 for Tsagan Teg, the “White Mountain” locality in the southeastern Gobi Desert, this long-snouted member of the armored, tail-club-wielding ankylosaurs may have had a prominent bony ring around its eyes.

Tsintaosaurus
Taxon: Iguanodontia Hadrosauridae Lambeosaurinae
Name means: “Qingdao lizard”
Pronounced: CHING-DOW-SAWR-us or sin-TOU-SAW-rus
Length: 33 ft (10 m)
Time: Late Cretaceous, c. 71 mya
Place: China

This hadrosaur apparently bore a thin, hollow, horn-like crest that projected forward and upward from its forehead. Some scientists believed that this crest was merely a displaced bone, forced upwards by skull deformation during fossilization. The discovery of a second skull with a similar bone spike, however, suggests that it was a genuine feature of the plant-eating duckbill in life. Tsintaosaurus was named in 1958.

Tuojiangosaurus
Taxon: Stegosauria
Name means: “Tuo River lizard”
Pronounced: TOO-oh-jee-ANG-guh-SAW-rus
Length: 23.5 ft (7 m )
Time: Late Jurassic, 163 – 150 mya
Place: China

Tuojiangosaurus was the first Asian stegosaur ever unearthed and remains the best-known stegosaur from that region. Known from a nearly complete skeleton, Tuojiangosaurus had a typical stegosaurian skull with an elongated face and spoon-shaped teeth. Two rows of almost triangular plates stretched across the dinosaur’s back, from its neck over its shoulders, ending at the middle of its tail. Four defensive spikes adorned the tip of its powerful tail and probably provided a potent deterrent to any predator approaching from the rear. Tuojiangosaurus was named in 1977 for the Tuo River in Sichuan Province, China.

Turanoceratops
Taxon: Ceratopsia
Name means: “Turanian horned face”
Pronounced: tuh-RAN-uh-SER-uh-tops
Length: Small
Time: Late Cretaceous, c. 97.5 - 65 mya
Place: Russia, Central Asia

Named for the Turkistan region of Central Asia, this apparent small horned dinosaur, if confirmed as a ceratopsian, will be among the first members of the family Ceratopsidae to be known from Asia. Although it was named in 1989, little is known about Turanoceratops at present.

Tylocephale
Taxon: Pachycephalosauria
Name means: “swelling head”
Pronounced: TYE-luh-SEF-uh-lee
Length: 7 ft (2.5 m)
Time: Late Cretaceous, 80 – 75 mya
Place: Mongolia

Described based on the excavation of a damaged skull, this bone-headed dinosaur was unique among pachycephalosaurids in that its dome is unusually elevated in the front. Named in 1974, the small but sturdy Tylocephale ate plants and may have engaged in ritual head-butting with other members of its species.

Tylosteus
Name means: “swelling bone”
Pronounced: tye-LOH-stee-us
This dinosaur is now considered to be PACHYCEPHALOSAURUS.

Tyrannosaurus
Taxon: Theropoda Coelurosauria Tyrannosauridae
Name means: "tyrant lizard"
Pronounced: tye-RAN-uh-SAW-rus
Length: 33 – 46 ft (10 - 14 m)
Time: Late Cretaceous, 68 - 65 mya
Place: Montana, Wyoming, Colorado, New Mexico,
South Dakota, Canada, Mongolia, China

Perhaps the most famous and most popular of big, carnivorous theropods, Tyrannosaurus is often considered the reigning king of dinosaurian ferocity. Although it may not have been the biggest meat-eater, it has established a huge reputation through the years as one of the most powerful meat-eaters ever to roam the earth. Tyrannosaurus was a giant carnivore with a massive, dagger-toothed skull capable of delivering a powerful, bone-shearing bite. Low, bumpy crests sat above its eyes. The two-clawed arms, although too short to reach the mouth or even to touch one another, appear to have been strongly muscled. The manner of tyrannosaur feeding remains a subject of debate. Some experts believe that they were simply not swift enough to pursue prey and may have been pure scavengers, using their powerful sense of smell to locate the carcasses of already-dead animals. More popular theories suggest that tyrannosaurs could indeed have chased down prey, or that they may have been ambush hunters, lurking under cover of Late Cretaceous forests for a hadrosaur or ceratopsian to wander too close, and then lunging out to deliver a single, spine-crushing bite to cripple or kill the hapless plant-eater. Recent fossil finds have suggested that tyrannosaurs may have gathered or hunted together, perhaps in small family groups. Tyrannosaurus was named in 1905.