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 the slightly older Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus, while others maintain Tarbosaurus as a separate genus.

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 weighing as much as an elephant.

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.

Acrocanthosaurus (pronunciation: ak-ro-KAN-tho-SAWR-us) is a genus of carnosaurian theropod dinosaur from the mid-Cretaceous Period of what is now North America. It was one of the largest bipedal carnivorous dinosaurs, with one mounted specimen reaching a length of 11.5 meters (38.3 feet) and an estimated weight of 4.16 metric tonnes (4.6 tons). Many of its vertebrae had high neural spines.

Sauroposeidon was a sauropod from the Early Cretaceous Period, related to the more famous Brachiosaurus. The only specimen to date is represented by four neck vertebrae. It was the tallest dinosaur known, estimated at 18 m (60 ft).

Its name is Greek for "lizard-Poseidon". The Greek sea-god Poseidon was also known as Ennosigaios or Enisokhthōn = "Earthshaker". The reference here is to the ground shaking under its weight as it walked: compare Seismosaurus.

Velociraptor (meaning "swift thief") is a genus of dromaeosaurid theropod dinosaur that existed approximately 83 to 70 million years ago during the later part of the Cretaceous Period. There is only one universally recognized species, V. mongoliensis, although others have been attributed in the past. Fossils of this species have been found in central Asia, from both Inner and Outer Mongolia.

Smaller than other dromaeosaurids like Deinonychus and Achillobator, the turkey-sized Velociraptor nevertheless shared many of the same anatomical features. It was a bipedal carnivore with a long, stiffened tail and had an enlarged, sickle-shaped claw on each hindfoot, which is thought to have been used to kill its prey. Velociraptor can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout.

Due in large part to its prominent role in Michael Crichton's novel Jurassic Park and the subsequent motion picture series, Velociraptor (commonly shortened to 'raptor') is one of the dinosaur genera most familiar to the general public. It is also well-known to paleontologists, with over a dozen recovered fossil skeletons — the most of any dromaeosaurid. One particularly famous specimen shows a Velociraptor locked in combat with a Protoceratops.

Dracorex is a dinosaur genus of the family Pachycephalosauridae, from the Late Cretaceous of North America. The type (and only) species is Dracorex hogwartsia, meaning "dragon king of Hogwarts". It is known only from one nearly complete skull discovered in the Hell Creek Formation in South Dakota by three amateur paleontologists from Sioux City, Iowa. The skull was subsequently donated to the Children's Museum of Indianapolis for study in 2004, and was formally described by Bob Bakker and Robert Sullivan in 2006.

Jaxartosaurus was a hadrosaur similar to Corythosaurus which lived during the Late Cretaceous. Its fossils were found in China. It had a large, helmet-like crest that it used to vocalize with members of the same herd. Females had the smallest crests, and juveniles had none at all.

The type species, J. aralensis, was first described by Riabinin in 1937. A second species, J. fuyunensis, was described by Weishampel and Horner in 1990, but is dubious.

Zuniceratops ('Zuni-horned face') was a Ceratopsian dinosaur from the mid Turonian of the Late Cretaceous Period of what is now New Mexico, USA. It lived about 10 million years earlier than the more familiar horned Ceratopsidae and provides an important window on their ancestry.

Zuniceratops appears to have been roughly 10-11 feet (three to 3.5 meters) long and three feet (one meter) tall at the hips. It probably weighed 200 to 250 pounds (100 to 150 kilograms). The frill behind its head was fenestrated but lacking exoccipitals. It is the earliest-known ceratopsian to have eyebrow horns and the oldest-known ceratopsian from North America. This set of horns is thought to have grown much larger with age.

Fulengia is the name given to a genus of dinosaur from the Early Jurassic. It was a prosauropod or other basal sauropodomorph. Its fossils were found in China.

The type species, Fulengia youngi, was described by Carroll and Galton in 1977. It is a nomen dubium, and may be the same animal as Lufengosaurus (from which it is anagramized). It was originally thought to be a lizard.

Stygimoloch ("river devil") was a pachycephalosaurid that lived during the Cretaceous Period between 68-65 million years ago in what is now North America. This dinosaur measured about 10 feet long and bore a thick skull that was decorated with six large spikes that covered the top rim of its head. This may have served the dinosaur as a display of recognition, helping the dinosaur to identify its companions. This dinosaur was a plant-eater and it lived in herds for protection from predators such as Tyrannosaurus, Dromaeosaurus, and Gorgosaurus. Males would often challenge one another to battle, either for females with which to mate, or for supremacy in the herd. [citation needed] It was previously thought that, like goats, they would butt heads with each other until one weakened and backed off, leaving the victor to choose a female or to lead a herd. However, the lack of apparent cranial damage exhibited by recent fossil discoveries has given rise to the hypothesis that they did not actually butt heads with other members of the herd. Some conjecture that stygimoloch headbutted other dinosaurs in their much softer underbelly regions.

Itemirus is the name given to a genus of dinosaur from the Late Cretaceous. It was a possible Tyrannosaurid which lived in Asia. A fossil of its braincase was found at Dzharakuduk.

The type species, I. medullaris, was described by Kurzanov in 1976. No other species have been permanently assigned to this genus. Since only the braincase was discovered, the only certain estimates concern its brain size, and evidence that it had good vision and balance, based on the large lobes of the brain.

Draconyx was a genus of dinosaur from the Late Jurassic. It was an Iguanodont which lived in what is now Portugal. It was described by Mateus and Antunes in 2001. The type specimen, known from only partial remains, is Draconyx loureiroi.

Unenlagia (meaning "half-bird") was a genus of theropod dinosaur of the family Dromaeosauridae. Unenlagia, which lived in South America during the Late Cretaceous, was a member of the strange and extremely bird-like Gondwanan sub-family of dromaeosaurs called unenlagiines, and was closely related to dinosaurs such as Buitreraptor and Neuquenraptor (which might be the same species as Unenlagia). Makovicky (2005) suggested that the 'flying raptor' Rahonavis is also a member of this group, which could mean that Unenlagia is secondarily flightless, having evolved from flying, Rahonavis-like ancestors.

Unenlagia was very birdlike itself. Novas and Puerta (1997) found its pelvic region to be very similar to that of the early bird Archaeopteryx. The shoulder girdle of Unenlagia also shows adaptations for flapping and, since at 2 meters (6 feet) long Unenlagia was probably too big to fly, this provides further evidence that it evolved from flying ancestors.