Post by Just some guy on Mar 28, 2014 18:28:23 GMT -5
Tyrannosaurus rex
Tyrannosaurus (/tɨˌrænəˈsɔrəs/ or /taɪˌrænəˈsɔrəs/; meaning "tyrant lizard", from Greek tyrannos (τύραννος) meaning "tyrant", and sauros (σαῦρος) meaning "lizard"[1]) is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, which then was an island continent named Laramidia, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 67 to 66 million years ago.[2] It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hindlimbs, Tyrannosaurus forelimbs were short but were unusually powerful for their size and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and was also one of the largest known land predators; the most complete specimen measures up to 12.3 m (40 ft) in length,[3] up to 4 metres (13 ft) tall at the hips,[4] and up to 6.8 metric tons (7.5 short tons) in weight.[5] By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs, ceratopsians, and possibly sauropods,[6] although some experts have suggested it was primarily a scavenger. The debate about whether Tyrannosaurus was an apex predator or scavenger was among the longest running in paleontology; however, most scientists now agree that Tyrannosaurus rex was an opportunistic carnivore, both predating and scavenging.[7] More than 50 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology; e.g., life history and biomechanics. The feeding habits, physiology and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial: some scientists consider Tarbosaurus bataar from Asia to be a second species of Tyrannosaurus and others maintaining Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.
Credit goes to puntotu for the Tyrannosaurus illustration.
Elasmotherium sibiricum
Elasmotherium ("Thin Plate Beast") is an extinct genus of giant rhinoceros endemic to Eurasia during the Late Pliocene through the Pleistocene, documented from 2.6 Ma to as late as 50,000 years ago, possibly later, in the Late Pleistocene, an approximate span of slightly less than 2.6 million years. Three species are recognised. The best known, E. sibiricum was the size of a mammoth and is thought to have borne a large, thick horn on its forehead which was used for defense, attracting mates, driving away competitors, sweeping snow from the grass in winter and digging for water and plant roots. Like all rhinoceroses, elasmotheres were herbivorous. Unlike any others, its high-crowned molars were ever-growing. Its legs were longer than those of other rhinos and were adapted for galloping, giving it a horse-like gait. Various theories of Elasmothere morphology, nutrition and habits have been the cause of wide variation in reconstruction. Some show the beast trotting like a horse with a horn; others hunched over with head to the ground, like a bison, and still others immersed in swamps like a hippopotamus. The use of the horn and whether or not there was one, and how large, have been popular topics. The statistical correlations of modern paleontology have taken much of the speculation out of the subject, although some details remain undetermined. The known specimens of E. sibiricum reach up to 4.5 m (15 ft) in body length with shoulder heights over 2 m (6 ft 7 in) while E. caucasicum reaches at least 5 m (16 ft) in body length with an estimated mass of 3.6–4.5 tonnes (4–5 short tons), based on isolated molars that significantly exceed those known from the Siberian species.[6] Both species were among the largest in the family Rhinocerotidae, comparable in size to the woolly mammoth and larger than the contemporary woolly rhinoceros.[7][8] The feet were unguligrade, the front larger than the rear, with 4 digits at the front and 3 at the rear.[9]
Credit goes to avancna for the Elasmotherium illustration
Tyrannosaurus (/tɨˌrænəˈsɔrəs/ or /taɪˌrænəˈsɔrəs/; meaning "tyrant lizard", from Greek tyrannos (τύραννος) meaning "tyrant", and sauros (σαῦρος) meaning "lizard"[1]) is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, which then was an island continent named Laramidia, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 67 to 66 million years ago.[2] It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hindlimbs, Tyrannosaurus forelimbs were short but were unusually powerful for their size and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and was also one of the largest known land predators; the most complete specimen measures up to 12.3 m (40 ft) in length,[3] up to 4 metres (13 ft) tall at the hips,[4] and up to 6.8 metric tons (7.5 short tons) in weight.[5] By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs, ceratopsians, and possibly sauropods,[6] although some experts have suggested it was primarily a scavenger. The debate about whether Tyrannosaurus was an apex predator or scavenger was among the longest running in paleontology; however, most scientists now agree that Tyrannosaurus rex was an opportunistic carnivore, both predating and scavenging.[7] More than 50 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology; e.g., life history and biomechanics. The feeding habits, physiology and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial: some scientists consider Tarbosaurus bataar from Asia to be a second species of Tyrannosaurus and others maintaining Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.
Credit goes to puntotu for the Tyrannosaurus illustration.
Elasmotherium sibiricum
Elasmotherium ("Thin Plate Beast") is an extinct genus of giant rhinoceros endemic to Eurasia during the Late Pliocene through the Pleistocene, documented from 2.6 Ma to as late as 50,000 years ago, possibly later, in the Late Pleistocene, an approximate span of slightly less than 2.6 million years. Three species are recognised. The best known, E. sibiricum was the size of a mammoth and is thought to have borne a large, thick horn on its forehead which was used for defense, attracting mates, driving away competitors, sweeping snow from the grass in winter and digging for water and plant roots. Like all rhinoceroses, elasmotheres were herbivorous. Unlike any others, its high-crowned molars were ever-growing. Its legs were longer than those of other rhinos and were adapted for galloping, giving it a horse-like gait. Various theories of Elasmothere morphology, nutrition and habits have been the cause of wide variation in reconstruction. Some show the beast trotting like a horse with a horn; others hunched over with head to the ground, like a bison, and still others immersed in swamps like a hippopotamus. The use of the horn and whether or not there was one, and how large, have been popular topics. The statistical correlations of modern paleontology have taken much of the speculation out of the subject, although some details remain undetermined. The known specimens of E. sibiricum reach up to 4.5 m (15 ft) in body length with shoulder heights over 2 m (6 ft 7 in) while E. caucasicum reaches at least 5 m (16 ft) in body length with an estimated mass of 3.6–4.5 tonnes (4–5 short tons), based on isolated molars that significantly exceed those known from the Siberian species.[6] Both species were among the largest in the family Rhinocerotidae, comparable in size to the woolly mammoth and larger than the contemporary woolly rhinoceros.[7][8] The feet were unguligrade, the front larger than the rear, with 4 digits at the front and 3 at the rear.[9]
Credit goes to avancna for the Elasmotherium illustration
