Theropods

Daemonosaurus chauliodus

A newly discovered dinosaur species bridges the gap between the earliest known group of predators and more advanced beasts such as Tyrannosaurus rex, according to a new study. Found at New Mexico's Ghost Ranch fossil site, the primitive dinosaur lived about 205 million years ago. The dinosaur, which stood as tall as a large dog, boasts a very unusual skull, said study co-author Hans-Dieter Sues, a vertebrate paleontologist at the National Museum of Natural History in Washington, D.C. "It has a deep, short snout and these monstrous front teeth. That's a kind of skull structure for a predatory dinosaur that's really unexpected for this early point in time," Sues said. These features helped earn the new dinosaur the name "buck-toothed evil spirit" in Greek. The oldest known dinosaurs lived in what's now South America during the late Triassic Period, some 230 million years ago. This group included early versions of two-legged predators known as theropods.

Altispinax

ALTISPINAX Pronunciation: al-tuh-SPY-nax Translation: High Spines Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Family: (Not confirmed) Height: 11 feet (3.4 meters) Length: 26.2 feet (8 meters) Weight: Period: Early Cretaceous Notes: Fragmentary remains of this dinosaur have been discovered in England and Germany. Only some worn teeth and three mid-back vertebrae are known. On these vertebrae were long projections similar to, but shorter than, those of Spinosaurus.

Archaeopteryx

Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Aves Height: 1 foot (0.3 meters) Length: 3 feet (0.9 meters) Weight: 2 lbs (0.9 kg) Period: Late Jurassic Notes: Identified by many as the first bird, resembles a coelurosaur but was covered in feathers. (Its remains were found in fine grained stone which still bore the clear impression of its feathers.) This dinosaur was 3 feet (0.9 meters) long with sharp teeth, a long bony tail, and claw fingers on its wings. The only known member of this family was discovered in Bavaria, Germany. There is considerable debate whether this dinosaur and Mononychus should be classified as dinosaurs.

Acrocanthosaurus

Infraorder: Tetanurae Micro-order: Carnosauria Family: Allosauridae(not confirmed) Height: 18 feet (5.5 meters) Length: 40 feet (12.2 meters) Weight: 4,000 - 6,000 lbs (1,814 - 2,722 kg) Period: Early Cretaceous Notes: This dinosaur is one of the few allosaurids known to North America, with fragmentary remains having been found in Texas and Oklahoma. Its back was marked by spines of up to 2 feet (60 cm) high in large specimens. Unlike the spines in other dinosaurs, those in this dinosaur were thickly covered with muscle, and it is unlikely that this ridge was used for cooling. (Compare Spinosaurus) It is estimated that this dinosaur could run as fast as 25 mph (40 km/h).

Afrovenator

Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Height: 10 feet (3.0 meters) Length: 29.5 feet (9 meters) Weight: 3,000 pounds (1,361 kg) Period: Early Cretaceous Discovered in Niger in the southern Sahara Desert in Africa, this dinosaur shows some similarities in appearance to Torvosaurus; e.g. similar forelimbs. It possessed 14 blade-shaped teeth. Known from a partial skeleton and a nearly complete skull, this dinosaur was an exciting find because dinosaur fossils are scarce in northern Africa.

Adasaurus

Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Dromaeosauridae Height: Length: 6 feet (1.8 meters) Weight: 33 lbs (15 kg) Period: Late Cretaceous Notes: As in other dromaeosaurs, the this dinosaur's hip bone is arranged more like that of an ornithischian than other saurischians. This dinosaur had a "switchblade" toe claw similar to, but smaller than those of other dromaeosaurids like Deinonychus and Velociraptor.

Albertosaurus

Translation: Alberta Lizard Also known as: Gorgosaurus, Deinodon Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae Height: 15 feet (4.5 meters) Length: 30 feet (11 meters) Weight: 6,000 lbs (2,722 kg) Period: Late Cretaceous Notes: First discovered in Alberta, Canada, this dinosaur stalked its prey almost 8 million years before Tyrannosaurus, a close relative. It had a huge head with long, sharp, saw-toothed teeth and two-fingered hands on arms that were longer than Tyrannosaurus's stubby forelimbs. With its sleek build and long hind limbs, it was one of the fastest runners among the tyrannosaurids. A jaw and teeth belonging to this dinosaur were identified by Joseph Leidy, who named the first American dinosaurs (see Deinodon).

Alvarezsaurus

Translation: Alvarez (Don Gregorio Alvarez) Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Alvarezsauria (of the microorder Coelurosauria) Family: Alvarezsauridae Height: 2 feet (0.6 meters) Length: 4.6 feet (1.4 meters) Weight: 6.6 lbs (3 kg) Period: Late Cretaceous Notes: Discovered in Neuquen, Argentina, the remains of this dinosaur did not include a skull or forelimbs. A small animal, it was lightly built with long legs, suggesting that it could run quickly. One odd characteristic of this genus is the lack of spines on the neck vertebrae. Some scientists believe this dinosaur is related to the Mongolian Mononychus.

Alxasaurus

Translation: Alxa (Alxa Desert of Inner Mongolia) Lizard Also known as: Description: Herbivore, mostly Bipedal? Order: Saurischia Suborder: Theropoda Infraorder: Therizinosauroidea Family: Alxasaururidae Height: 5.75 feet (1.75 meters) Length: 13 feet (4 meters) Weight: Period: Early-Late Cretaceous Notes: This unusual dinosaur is the earliest known Segnosaur. It is characterized by its large arms and claws. It closely resembled Erlikosaurus in structure; one of the more notable anatomical differences being a greater number of teeth possessed by vs. 31 in Erlikosaurus. While it had a toothless beak, these tiny, leaf-shaped teeth were placed further back in the mouth and are usually interpreted as being those of a herbivore.

Archaeornithomimus

Translation: Ancient Bird Mimic Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Superfamily: Ornithomimosauria (of the microorder Coelurosauria) Family: Ornithomimidae Height: 6 feet (1.8 meters) Length: 11 feet (3.4 meters) Weight: 200 pounds (90.7 kg) Period: Late Cretaceous Notes: Found in China, Archaeornithomimus is the oldest ornithomimid or ostrich mimic dinosaur. Unlike its later cousins which had three long fingers on each hand this dinosaur had a small, short third finger and all the hand bones are much shorter than any other ornithomimid. This finding has lead some scientists to question whether This dinosaur is a true ornithomimid or a new and as yet unidentified carnivorous dinosaur.

Aublysodon

Translation: Backward Tooth Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae (not confirmed) Subfamily: Aublysodontinae Height: Length: 15 feet (4.5 meters) Weight: Period: Late Cretaceous Notes: Named in the nineteenth century from fragmentary remains, this dinosaur has had many unidentified fossils assigned to it. It may have been a tyrannosaurid.

Bahariasaurus

Translation: Baharije Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Height: Length: Weight: Period: Cretaceous Notes: The name was given to fragmentary remains found in Egypt. It was probably similar to Megalosaurus.No further study of this dinosaur is possible until new specimens are identified, for its remains were destroyed in the World War II bombing of Stuttgart, Germany.

Avimimus

Translation: Bird Mimic Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Superfamily: Ornithomimosauria (of the microorder Coelurosauria) Family: Avimimidae Height: 3.5 feet (1.1 meters) Length: 5 feet (1.5 meters) Weight: Period: Late Cretaceous Notes: Fossils of Avimimus have been found in Mongolia and China. A small, birdlike dinosaur, this dinosaur was probably a swift runner, preying upon lizards and insects. Although the idea is disputed, this dinosaur may have had feathered wings. It is distinct enough from other theropods to merit its own family.

Genyodectes

Translation: Biting Jaw Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda (not confirmed) Family: Height: Length: Weight: Period: Late Cretaceous (not confirmed) Notes: Found in Argentina, this dinosaur is known from fragmentary skull remains, characteristics of which are similar to Carnotaurus.

Chilantaisaurus

Translation: Chilantai (Mongolian river) Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Allosauridae Height: 9 feet (2.7 meters) Length: 20 feet (6.1 meters) Weight: 8,000 lbs (3,630 kg) Period: Late Cretaceous Notes: Known from fragmentary remains found in Mongolia and China, this dinosaur seems to have resembled Allosaurus, but it may have been related to the tyrannosaurids as well. This dinosaur had large arms for a big theropod.

Chingkankousaurus

Translation: Chingkankou (Chinese village) Lizard Also known as: Description: Carnivore,y Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae Height: Length: Weight: Period: Late Cretaceous Notes: This dinosaur is known only from a shoulder blade found in China. Notes: None

Chindesaurus

Translation: Chinle (from Chinde Point in Petrified Forest) Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Ceratosauria Family: Herrerasauridae (not confirmed) Height: 4 feet (1.2 meters) Length: 11.5 feet (3 meters) Weight: 120 pounds (54.4 kg) Period: Late Triassic Notes: This dinosaur was discovered in Arizona's Upper Petrified Forest formation at Chinde Point. This apparent herrerasaurid was similar in size and shape to Ischisaurus. Its neck was lightly-built and moderately long. The body was compact, possessing relatively long hind limbs and a longer tail than Ischisaurus. If it is a herrerasaurid, then it is the first definite member of this important family of dinosaurs in North America.

Eoraptor

Translation: Dawn Plunderer Also known as: Description: Carnivore, Bipedaly Order: Saurischia Suborder: Theropoda Family: Height: 20 inches (0.5 meters) Length: 36 inches (0.9 meters) Weight: 8 pounds (3.6 kg) Period: Late Triassic Notes: Discovered in Argentina in 1991 by a team led by Paul Sereno of the University of Chicago, this dinosaur is the most primitive dinosaur known -- 228 million years old. This find, coupled with the discoveries of Staurikosaurus and Herrerasaurus in South America, has led some scientists to suspect that the region is the cradle of Dinosauria.

Compsognathus

Translation: Elegant Jaw Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria (not confirmed) Family: Compsognathidae Height: 24 inches (0.6 meters) Length: 40 inches (1.0 meters) Weight: 8 lbs (3.6 kg) Period: Late Jurassic Notes: This dinosaur was once the smallest known dinosaur -- about the size of a chicken. Because of its size and the lightness of its bones, it is believed that this dinosaur was a very swift predator. It has been suggested that this dinosaur was feathered, but as it was discovered in the same lithographic limestone in which Archaeopteryx was found and yet showed no feather impressions, a feathered this dinosaur is unlikely.

Dromiceiomimus

Translation: Emu Mimic Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Superfamily: Ornithomimosauria (of the microorder Coelurosauria) Family: Ornithomimidae Height: 6 feet (1.8 meters) Length: 11 feet (3.4 meters) Weight: 220 pounds (99.8 kg) Period: Late Cretaceous Notes: Discovered in Alberta, Canada, this dinosaur was probably one of the most intelligent dinosaurs of the Cretaceous Period, with a brain larger than that of an ostrich. It was also a swift runner, capable of speeds up to 40 mph (64 km/h). Its relatively weak jaws had no teeth, but as there is no evidence that Dromicieomimus swallowed stones for use in digestion, it is unlikely that it ate plants. Its hands are well-adapted for digging, which suggests that it ate insects and eggs. Because of the large size of its pelvic canal, Dromiceiomimus may have given birth to its young, rather than laying eggs.

Erlikosaurus

Translation: Erlik's Lizard Also known as: Description: Herbivore, Bipedal? Order: Saurischia Suborder: Theropoda Infraorder: Family: Therizinosauridae Height: 9 feet (2.7 meters) Length: 16 feet (4.9 meters) Weight: Period: Late Cretaceous Notes: An unusual kind of dinosaur that lived in Mongolia, its name is derived from the Lamaist deity Erlik. It had a long, slender, toothless beak. However, further back in its mouth were rows of tiny leaf-shaped teeth usually associated with herbivores like Lesothosaurus and the prosauropods. Recent analysis indicates that they are theropods but unlike most theropods, they have four big toes on each foot instead of the typical three.

Archaeornithoides

Translation: First Bird Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Archaeornithoididae Height: Length: 3.3 feet (1 meter) Weight: Period: Late Cretaceous Notes: This dinosaur is the among the smallest of dinosaurs. Many of its bones resemble those of modern birds, hence its name, but the bones also indicate a kinship with the troodontids and spinosaurids.

Elmisaurus

Translation: Foot Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Elmisauridae Height: 3.3 feet (1 meter) Length: 6.6 feet (2 meters) Weight: Period: Late Cretaceous Notes: The identification of this dinosaur is based upon the discovery of a single, distinctive foot. There are similarities between this foot and those of other theropods, but the differences indicate that it is in a class of its own.

Frenguellisaurus

Translation: Frenguelli Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda (not confirmed) Infraorder: Ceratosauria Family: Staurikosauridae Height: Length: Weight: 770 pounds (349 kg) Period: Late Triassic Notes: Discovered in Argentina, Frenguellisaurus is thought to be related to Staurikosaurusbecause of its similar hip structure. Many others believe it to be a Herrerasaurus.

Daspletosaurus

Translation: Frightful Lizard Also known as: Description: Carnivore,Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae Height: 16 feet (4.9 meters) Length: 30 feet (9.1 meters) Weight: 5,950 lbs (2,700 kg) Period: Late Cretaceous Notes: Discovered in Alberta, Canada, this dinosaur was a contemporary of Albertosaurus. A marginally smaller, close relative of Tyrannosaurus, this dinosaur possessed the typical tyrannosaurid two-fingered hands, but its powerful jaws were equipped with larger (although fewer) teeth than Tyrannosaurus. It is conjectured that the heavily-built Daspletosaurus preyed upon ceratopsians.

Gasosaurus

Translation: Gas Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae (not confirmed) Micro-order: Carnosauria Family: Height: Length: 12 feet (3.5 meters) Weight: Period: Middle Jurassic Notes: Known from fragmentary remains, this dinosaur is thought to be a small carnosaur. It was named for the natural gas company employees in China who discovered it.

Baronyx

Translation: Heavy Claw Also known as: Description: Carnivore, Bipedal, semi Quadrupedal Order: Saurischia Suborder: Theropoda Family: Height: 6 feet (1.8 meters) Length: 30 feet (9.1 meters) Weight: 4,000 lbs (1,814 kg) Period: Early Cretaceous Notes: Discovered in southern England, this dinosaur had a huge curved claw over 12 inches (30-cm) in length on each hand. Its long narrow jaws were equipped with small pointed teeth, twice as many as a theropod would normally have, which leads many to think that this dinosaur was a fisher. It might have waded in shallow water to spear fish with its claws.

Coelophysis

Translation: Hollow Form Also known as: Rioarribasaurus Description: Carnivore,Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Ceratosauria Family: Podokesauridae Height: 4 feet (1.2 meters) Length: 9 feet (2.7 meters) Weight: 100 lbs (45.5 kg) Period: Late Triassic Notes: This dinosaur was an early theropod that is thought to have lived in family groups and hunted in packs. Much of what is deduced of this dinosaur behavior is based on the hundreds of well-preserved skeletons found at Ghost Ranch, New Mexico. This dinosaur has recently been renamed "Rioarribasaurus," but some researchers believe that these are two different animals.

Coelurus

Translation: Hollow Tail Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda (not confirmed) Family: Height: 3 feet (0.9 meter) Length: 6 feet (1.8 meters) Weight: Period: Late Jurassic Notes: This dinosaur takes its name from the very light bones (vertebrae, foot and leg bones, and parts of the pelvis) that are among the fragmentary remains recovered in Wyoming. The lightness of its bones suggests that this dinosaur was a very fast moving dinosaur.

Halticosaurus

Translation: Leaping Lizard Also known as: Coelurosaur Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda (not confirmed) Family: Height: 8 feet (2.4 meters) Length: 18 feet (5.5 meters) Weight: Period: Late Triassic Notes: This small dinosaur was one of the first known theropods, discovered in southern Germany in 1906.

Elaphrosaurus

Translation: Lightweight Lizard Also known as: Description: Carnivore,Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Superfamily: Ornithomimosauria (of the microorder Coelurosauria) Family: Ornithomimidae Height: 6.5 feet (2 meters) Length: 11 feet (3.4 meters) Weight: Period: Late Jurassic Notes: This dinosaur was discovered in Africa and North America. One of the earliest members of the ornithomimid family, it was a very lightweight, fast predator. Its hands and feet each had three digits.

Carnotaurus

Translation: Meat-Eating Bull Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Ceratosauria Family: Abelisauridae Height: 13 feet (4 meters) Length: 24.6 feet (7.5 meters) Weight: 1,984 lbs (900 kg) Period: Early Cretaceous Notes: A strange-looking dinosaur with a short snout, two bull-like horns, a weak jaw and small eyes. A skin cast discovered in southern Argentina reveals that this dinosaur in life had a reptilian, pebbly skin. This skin cast is the very best yet found for a theropod.

Enigmosaurus

Translation: Mysterious Lizard Also known as: Description: Herbivore, Bipedal? Order: Saurischia Suborder: Theropoda Infraorder: Family: Therizinosauridae Height: 10 feet (3 meters) Length: 23 feet (7 meters) Weight: Period: Late Cretaceous Notes: As its name suggests, this dinosaur is known only from the fragmentary remains of its pelvis. Though classified as a saurischian, this dinosaur had a peculiar reverted pubis seen in the dromaeosaurids, but they are not closely related to that group.

Chirostenotes

Translation: Narrow Hand Also known as: Macrophalangia Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Elmisauridae Height: 3.5 feet (1.1 meters) Length: 7 feet (2.1 meters) Weight: Period: Late Cretaceous Notes: This dinosaur is known from fragmentary remains found in Alberta, Canada. Each hand had three narrow, clawed fingers, with the middle finger being considerably longer than the others. Also discovered in the same formation was Macrophalangia, and when a partial skeleton was later recovered, it was determined that Macrophalangia and this dinosaur were the same creature.

Alioramus

Translation: Other Branch Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae Height: 11 feet (3.4 meters) Length: 20 feet (6.1 meters) Weight: 1,500 lbs (680 kg) Period: Late Cretaceous Notes: This dinosaur had a longer head and smaller and more numerous teeth than other tyrannosaurids. It was small and slender and it possessed six small horns on its long snout, two side by side and four in a single row ahead of them. Too small for defensive purposes, these horns may have been secondary sexual characteristics, identifying males and females. Fossils of this dinosaur were found in Mongolia.

Allosaurus

Translation: Other Lizard Also known as: Antrodemus, Creosaurus Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Allosauridae Height: 17 feet (5.2 meters) Length: 40 feet (12.2 meters) Weight: 4,000 lbs (1,814 kg) Period: Late Jurassic Notes: Allosaurus is one of the best known carnosaurs. Sixty individuals, from juveniles to adults, were found at one site in Utah. It is likely that Allosaurus may have been the most common carnosaur of the Late Jurassic. Despite its size, Allosaurus is thought to have been a speedy hunter, running with a 3.7-meter-long stride at up to 20 mph. Its most distinguishing characteristic is the presence of two short horns, above and in front of each eye.

Chirostenotes

Translation: Recent Jaw Also known as: Chirostenotes Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae (not confirmed) Micro-order: Maniraptora (of the microorder Coelurosauria) Superfamily: Oviraptorosauria Family: Caenagnathidae Height: Length: 6.6 feet (2 meters) Weight: Period: Late Cretaceous Notes: When first discovered, its remains suggested a more primitive animal than this dinosaur; and thus it should have been an earlier species. However, current theory holds that Caenagnathus, Macrophalangia and some material referred to Elmisaurus are all probably this dinosaur.

Calamospondylus

Translation: Reed Vertebra Also known as: Aristosuchus Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Coelurosauria (not confirmed) Family: Coeluridae Height: 3 feet (.9 meters) Length: 6.6 feet (2 meters) Weight: Period: Early Cretaceous Notes: A small meat-eater of uncertain identity; originally known as Aristosuchus. Found on the Isle of Wight, this dinosaur is distinguished by small toes but relatively large claws on its hands. Its most unusual feature is its pubic bone, the "foot" of which is considerably larger than that of most other carnivores, suggesting that this dinosaur had a large belly.

Carcharodontosaurus

Translation: Shark Tooth Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria (not confirmed) Family: Height: 23 feet (7.0 meters) Length: 45 feet (13.7 meters) Weight: 16,000 pounds (7,258 kg) Period: Cretaceous Notes: A 5 foot-4 inch skull of this dinosaur was recently discovered in North Africa. Based on this find, this dinosaur is clearly a worthy rival in size to the fearsome Tyrannosaurs rex. It had elongated spines on its neck vertebrae to accommodate the strong muscles that held up an enormous head with shark-like fangs. Named for a great white shark, fragmentary remains were first discovered in the early 1900's in Morocco.

Conchoraptor

Translation: Shell Thief Also known as: Description: Carnivore,Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Superfamily: Oviraptorosauria Family: Oviraptoridae Height: Length: 5 feet (1.5 meters) Weight: Period: Late Cretaceous Notes: This dinosaur possessed a short, deep head and a horny beak, similar to that of a parrot, with which it may have used to crush mollusks or eggs. Because its head has no crest, it may be that this dinosaur is actually a juvenile example of Oviraptor.

Bradycneme

Translation: Slow Leg or Heavy Shin Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Tro"dontidae(not confirmed) Height: Length: Weight: Period: Late Cretaceous Notes: This dinosaur is known only through a portion of a lower leg bone with a distinctive ankle joint. At one time, it was thought to be the fossil leg of a giant owl. The fossil was discovered in Transylvania.

Antrodemus

Translation: Strongly Framed Also known as: Allosaurus Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Allosauridae Height: 16.4 feet (5 meters) Length: 39.3 feet (12 meters) Weight: 8,000 lbs (3,630 kg) Period: Late Jurassic Notes: Scientists debate whether this dinosaur and Allosaurus are the same animal.

Dromaeosaurus

Translation: Swift Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Dromaeosauridae Height: 2.5 feet (0.8 meters) Length: 6 feet (1.8 meters) Weight: 100 pounds (45.4 kg) Period: Late Cretaceous Notes: This dinosaur was discovered in 1914 in the United States. It had razor-sharp teeth and 3 inch (7.6 cm) eagle-like claws on the inner toe of each foot. This dinosaur was first of the sickle-clawed dinosaurs to be discovered.

Dryptosaurus

Translation: Tearing Lizard, or Wounding Lizard Also known as: Laelaps Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria (not confirmed) Family: Dryptosauridae Height: 9 feet (2.7 meters) Length: 20 feet (6.1 meters) Weight: 3,000 pounds (1,360 kg) Period: Late Cretaceous Notes: This dinosaur was the first meat-eating dinosaur to be discovered in North America. Its most striking feature is the 8-inch (20-cm), talon-like claw with which each hand was equipped. Although this dinosaur is generally pictured as looking like Tyrannosaurus, recent thought makes it a coelurosaur.

Deinonychus

Translation: Terrible Claw Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Maniraptora (of the microorder Coelurosauria) Family: Dromaeosauridae Height: 5 feet (1.5 meters) Length: 9 feet (2.7 meters) Weight: 175 lbs (79.4 kg) Period: Early Cretaceous Notes: The discovery of this dinosaur in Montana in 1964 drastically altered the traditional view of dinosaurs as sluggish, slow-moving reptiles. This dinosaur was obviously built for speedy pursuit of its prey. Among other things, it had special interlocking vertebrae that allowed its tail to stiffen for balance while running. Excellent eyesight, sharp, serrated teeth that curve backwards for slicing, and the namesake 5-inch (13 cm) long, knife-like claws on each foot make Deinonychus a fearsome hunter. Five specimens were found together, leading to the theory that Deinonychus hunted in packs.

Deinocheirus

Translation: Terrible Hand Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Family: Height: Length: Weight: Period: Late Cretaceous Notes: Only a pair of arms belonging to this dinosaur have been discovered in southern Mongolia. These arms were very long -- 8 feet (2.4 meters) -- and their hands accounted for 2 feet (0.6 meters) of the length. The three fingered hands were equipped with formidable, 8 - 11 inch (20 - 30 cm), hook-like claws. This dinosaur may have used these spectacular claws to attack and kill prey, but it has also been suggested that it used them for climbing trees. Some scientists believe that this dinosaur may be a large Ornithomimosaur.

Deinodon

Translation: Terrible Tooth Also known as: Tyrannosaurus Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae Height: Length: Weight: Period: Late Cretaceous Notes: This dinosaur is known from fragmentary remains. Joseph Leidy, an anatomist from Philadelphia, named the first American dinosaurs in 1856 based on fossils brought back from Montana by Ferdinand Hayden. Leidy identified a jaw and 12 enormous teeth as belonging to a ferocious megalosaurid he christened Deinodon horridus. Upon further analysis of the remains since Deinodon's discovery, the dinosaur was determined to actually be Tyrannosaurus, making Deinodon an invalid dinosaur.

Dilophosaurus

Translation: Two-crested Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Ceratosauria Family: Podokesauridae Height: 8 feet (2.4 meters) Length: 20 feet (6.1 meters) Weight: Period: Early Jurassic Notes: This dinosaur takes its name from the delicate double crest on its head. This odd-appearing crest may have served as a secondary sexual characteristic, differentiating males from females. The fact that the jaws of this dinosaur are not as strong as other theropods of its size suggests that it may have dined on carrion. This dinosaur footprints found in trackways indicate that it traveled in groups.

Alectrosaurus

Translation: Unmarried Lizard Also known as: Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Tyrannosauridae Height: 7 feet (2.1 meters) Length: 16 feet (4.9 meters) Weight: less than 1,000 lbs (454 kg) Period: Late Cretaceous Notes: A small tyrannosaurid whose teeth were short but very sharp. Its hind legs were slender, as opposed to its thick-thighed relatives. It is known from fragments found in Mongolia.

Erectopus

Translation: Upright Foot Also known as: Description: Carnivore,Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Ceratosauria Family: Megalosauridae Height: Length: Weight: Period: Early Cretaceous Notes: Fragmentary remains of this dinosaur have been found in northern France, Egypt, and Portugal. This name was given because the animal apparently walked upright.

Eustreptospondylus

Translation: Well-Reversed Vertebrae Also known as: Streptospondylus Description: Carnivore, Bipedal Order: Saurischia Suborder: Theropoda Infraorder: Tetanurae Micro-order: Carnosauria Family: Eustreptospondylidae Height: 10 feet (3.0 meters) Length: 23 feet (7.0 meters) Weight: 2,500 pounds (1,134 kg) Period: Middle Jurassic Notes: The remains of this dinosaur were among the first to be named by Sir Richard Owen in 1841, one year before he published the term dinosaur for the first time. The skeleton of this carnivore is on display at the University Museum in Oxford. It resembles Meglosaurus, the first dinosaur to be named (1824). Eustreptospondylus was related to Allosaurus which appeared in the Late Jurassic. Its head was large, and its long jaws were lined with sharp, serrated teeth.