Tyrannosaurus rex (T-rex)
Tyrannosaurus rex (Greek for “tyrant lizard king”), or more commonly abbreviated as T. rex, is a species of tyrannosaurian theropod dinosaur that flourished during the Maastrichtian age of the Late Cretaceous epoch, 68-66 million years ago.
Ever since its discovery, Tyrannosaurus has become one of if not the popular of its kind; as over 50 individuals of this taxon have been unearthed. The most complete specimen of the T. rex was nicknamed “Sue” (located at Chicago’s Field Museum of Natural History, which is roughly 90% complete), measuring approximately 12.3+ meters (40+ feet) in length, around 3.8 meters high at the hips, and over 9 tonnes in weight, making it amongst the biggest terrestrial predators existed. There are other specimens estimated to be larger than Sue but this information is debated. However, one specimen, known as “Scotty”, measured 12.6 meters (43 feet) in length, stood 3.9 meters at the hips, and weighed nearly 11 tons.
Fossils have been uncovered in North and South Dakota, Texas, Montana, Colorado, Wyoming, and Saskatchewan within a depositional formation known as the “Hell Creek”. It was among the last non-avian dinosaurs to live prior to the K-T mass extinction event.
A rather recent, although controversial study indicates that there could be three differentiated and varied species of Tyrannosaurus and proposed two new species: Tyrannosaurus imperator and Tyrannosaurus regina. They are considered as invalid by most paleontologists, because the difference between these species can be explained with individual variation or sexual dimorphism.
Velociraptor
Velociraptor (ve·loc·i·rap·tor) (Latin meaning “swift seizer or thief”) was a small carnivorous dinosaur, well known thanks to Jurassic Park. It was one of the smaller dromaeosaurs, smaller than Utahraptor and Deinonychus, and was about 2 meters long. It lived in Mongolia and China during the Late Cretaceous, 75 to 71 million years ago. Fossils found in 2007 show that Velociraptor had long feathers on its forearms.
Velociraptor was a small theropod, with a large sickle-shaped claw on the second toe of its foot, and had a long, narrow, upturned snout, which is different from the other members of its family. The jaws were lined with serrated teeth for tearing flesh, it swallowed its food in gulps instead of chewing, like most theropods. The arms were long and it had strong chest and arm muscles, for grasping onto prey.
Like other dromaeosaurs, it had a falcarian claw on the second digit of its foot. This was raised off the ground, which can be seen in footprints of itself and other related dinosaurs.
Another dromaeosaurid feature that can be clearly seen in the death-pose are the long pieces of bone along the sides of the bones of the tail to stiffen it. This allowed the tail to act as a balance when the animal walked and ran. While this stiffened the vertical mobility, the tail could still swing side to side, possibly acting as a rudder during gliding.
Mamenchisaurus
Mamenchisaurus is an extinct genus of sauropod dinosaur including several species, known for their remarkably long necks of around 14 metres; which made up half the total body length.
It is known from numerous species which ranged in time from 160 to 145 million years ago, from the Oxfordian to Tithonian ages of the late Jurassic Period of China, and the largest species may have reached 35 meters (115 feet) in length and possibly weighed 50 to 75 tons. It is in the Mamenchisauridae.
Mamenchisaurus was first discovered in 1952 on the construction site of the Yitang Highway in Sichuan, China. The partial skeleton fossil was then studied, and named Mamenchisaurus constructus in 1954, by the renowned Chinese paleontologist Professor C. C. Young. The type specimen had an incomplete neck with 14 vertebra preserved and none of these were complete. M. constructus has been estimated around 13 m (43 ft) and 15 m (49 ft) in length.
In 1972, a second species was described, named Mamenchisaurus hochuanensis, with a neck that reached up to 9.3 m (31 ft) in length. This species had a complete neck preserved which contained 19 vertebrae This was the longest neck known until the description of Supersaurus, based on a single neck vertebra, BYU 9024, with an estimated neck length of about 14 meters (46 feet). Another long-necked sauropod exceeding M. hochuanensis was Sauroposeidon which was discovered in 1994. Based on the Sauroposeidon holotype, which only preserved 4 neck vertebra, its neck was estimated to be between 11.25 and 12 meters (36.9–39.4 feet) long.
Triceratops
Triceratops is an extinct genus of herbivorous ceratopsid dinosaur which lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 66.038 million years ago (mya) in what is now North America. Fossils seem to be most common in the United States. It was one of the last dinosaur genera to appear before the great Cretaceous and Tertiary extinction event Bearing a large bony frill and three horns on its large four-legged body, and conjuring similarities with the modern rhinoceros, Triceratops is one of the most recognizable of all dinosaurs. Although it shared the landscape with and was preyed upon by the fearsome Tyrannosaurus, it is unclear whether the two battled the way they are commonly depicted in movies, children’s dinosaur books and many cartoons.
A complete Triceratops skeleton has yet to be found however, the animal is well-known from numerous partial remains collected since the introduction of the genus in 1887. The function of their frills and three distinctive facial horns has long inspired debate. Although traditionally viewed as defensive weapons against predators, the latest theories claim that it is more probable that these features were used in courtship and dominance displays, much like the antlers and horns of modern reindeer, mountain goats, or rhinoceros beetles.
Triceratops is the best-known of the ceratopsids, though the genus’s exact placement within the group has been a point of contention amongst paleontologists. Two species, T. horridus and T. prorsus, are considered valid, although many other species have been
