Dinosaurs are the large animals which were part of our world, millions of years ago. But they vanished from the earth due to some distraction. No one knows clear about the reason. However, in the last century, their fossil remains had been discovered. They were largest animals on the earth at that time. We have collected information about twenty Scariest Dinosaurs based on the fossil remains discovered by scientists.
Giganotosaurus is a genus of theropod dinosaur that lived during the early Cenomanian age of the Late Cretaceous period, what is now Argentina, approximately 99.6 to 97 million years ago. The first specimen was found in 1993 in the Candeleros Formation of Patagonia and is almost 70% complete. The dinosaur got attention and became part of the debate about the maximum sizes of theropod dinosaurs. It was one of the largest known terrestrial carnivores. However, the exact size of Giganotosaurus is difficult to determine due to the incompleteness of the remains. Estimated length of a complete specimen ranges from 12 to 13 m, a skull 1.53 to 1.80 m in length and a weight of 4.2 to 13.8 t. The skull was low, with rugose nasal bones and a ridge-like crest on the lacrimal bone. It is one of a complete known members of the group, Carcharodontosauridae, which contains other large theropods. It was a slow moving animal with running speed of 50 km/h. It had the capability to capture and bring down prey using its powerful bites.
Liopleurodon is a genus of large, marine reptile related to the Pliosauroidea. They lived 160 to 155 years ago, during the Callovian stage of the Middle Jurassic Period. The largest species of Liopleurodon is estimated to have grown up to 6.39 m in length. The complete fossil remains have been discovered in France and England. They were powerful swimmers. By its skull study, it is estimated that it could scan the water to ascertain the source of specific smells. According to L. forex researchers, the largest known specimen of Liopleurodon was a little over 10 m. its body mass has been assumed at 1 and 1.7 tons for the lengths 4.8 and 7 m respectively. Their skulls were about one-fifth of their total body length. Liopleurodon was one of the basal taxa from the Middle Jurassic.
Ichthyosaurus is a genus of Ichthyosaurs from the late Triassic and early Jurassic of Europe and Asia. It is one of the best-known ichthyosaurs genera. It was the first complete fossil remains to be found in the early 19th century in England by Mary Anning. They were similar to most of their relatives, with individuals having a length of 2 meters. Hundreds of well-preserved fossilized skeletons are found in Jurassic rock at Holzmaden, Germany. Some remains still had baby specimens inside them. German fossil remains also had the outile of Ichthyosaurus’s skin, describing that it had a dorsal fin on the back and a large caudal fin. Ichthyosaurus had huge, sensitive eyes, protected by bony shields. According to researchers, its diet comprised of squid and fish. Fossil evidence describes that the female gave birth to live young and babies were born tail first stop them from drowning in the water.
Quetzalcoatlus northropi is an azhparchid pterosaur and one of the largest flying animals of all time. It is the member of a family of advanced toothless pterosaurs with unusually stiffened necks, the family Azharchidae. According to recent estimates, it has wingspan at 10 to 11 meters. Its fossil remains found in 1971 in Texas, which indicate that it had a minimum wingspan of 11 meters. Weight for a 10 meters individual estimated as 70 kilometers. Skull material shows that Quetzalcoatlus had a sharp and pointed beak. The first fossils were discovered from the Maastrichtian Javelina Formation dated to around 68 million years ago at Big Bend National Park in Texas, United States, in 1971 by Douglas A. Lawson. The specimen comprised a partial wing, from an individual at over 10 m in wingspan. They had precursors in North America. According to Lawson, Quetzalcoatlus scavenged like the marabour stork.
Tyrannosaurus is a genus of coelurosaurian theropod dinosaur. It is one of the well-represented of the large theropods. It lived throughout what is now western North America, on an island known as Laramidia. It had a much wider range than other tyrannosaurids. Fossil remains are found in a variety of rock formations, 68 to 66 million years ago, dating to the Maastrichtian age of the upper Cretaceous Period. Tyrannosaurus was the last known member of the tyrannosaurids. It was a bipedal carnivore with a heavy skull balanced by a long and heavy tail. Tyrannosaurus forelimbs were short but powerful for their size. The complete specimen measure up to 12.3 m in length, up to 3.666 m tall at the hips and up to 10.2 metric tons in weight. It was one of the largest known land predators and is assumed to have exerted the largest bite force among all land animals. Tyrannosaurus rex was an apex predator, preying upon ceratopsians, hadrosaurs, and sauropods. Over 50 specimens of Tyrannosaurus have been identified, most of them are complete skeletons. Proteins and soft tissue have been reported in one of these specimens.
Utahraptor is a genus of theropod dinosaurs. It comprises a single species, which is the largest member of the family Dromaeosauridae. Their fossils date to the upper Barremian stage of the early Cretaceous period, approximately 126 to 2.5 million years ago. The holotype specimen comprises a tibia, skull fragments, claws and some caudal vertebrae. It was an animal having a length twice of Deinonychus. It had large curved claws. One claw specimen is preserved at 22 cm in length and thought to reach 24 cm restored. The largest specimens of Utahraptor are estimated to have reached up to 7 meters long and less than 500 kg in weight, comparable to a polar bear in size. The first fossil remains of Utahraptor were found by Jim Jensen in 1975 in the Dalton Wells Quarry in east-central Utah. In October 1991, James Kirkland, Donald Burge, and Robert Gaston found many remains of Utahraptor in the Gaston Quarry in Grand County, Utah.
Moschops is an extinct genus of therapsid that lived around 265 to 260 million years ago in the Guadalupian epoch. They were at one time the dominant land animals. Moschops remains were found the Karoo region of South Africa. It was a massively built dinocephalian, with the rough length of 2.7 meters. Moschops had a thick, short and massive head. The skull of Moschops had a tiny opening for the pineal organ. Two species of Moschops are known from the good fossil record. This genus type was fictionalized in a stop motion animated Television series called Moschops.
Gorgonopsid is an extinct suborder of therapsid synapsids. Their mammalian specialization contains differentiated tooth shape, pillar-like rear legs, a fully developed fenestra, a vaulted palate and incipiently developed ear bones. These dinosaurs were a part of a group of therapsids called theriodonts. The largest species of Gorgonopsid was the size of a large bear with a 45-centimeter long skull, and 12 centimeters long saber-like teeth. The early Gorgonopsians were small, may be equal to the size of a dog. They evolved in the Middle Permian. Complete fossil remains of Gorgonopsid has been found in South Africa. They became extinct at the end of the Permian period, the only theriodont line to be finished by this mass extinction. Just like other therapsids, they were at one time called “mammals-like reptiles,” though “stem-mammals” is more correct.
Allosaurus is a genus of large theropod dinosaur that lived during the late Jurassic period 155 to 150 million years ago. Paleontologist Othniel Charles Marsh described the first fossil remains. Allosaurus has long attracted attention outside of the paleontological circle and was one of the first famous theropod dinosaurs. This genus of dinosaurs has been a top feature in different films and documentaries. It was a large bipedal predator, and its skull was large, with dozens of sharp, serrated teeth. According to its remains, Allosaurus could have reached over 12 meters. Its body was balanced by a heavily and long muscled tail. Allosaurus was at the top of the food chain, preying on large herbivorous dinosaurs and even other predators. Potential prey comprised stegosaurids, ornithopods, and sauropods. The discovery and early history of this genus is complicated by the many famous scientists during the Bone Wars of the 19th century.
Plesiosaurus is a genus of large and extinct marine sauropterygian reptile that lived during the Jurassic Period. There are many modern-day myths for this creatures. For example the myth of the Loch Ness Monster. It is notable by its small head, slender and long neck, a short tail, broad turtle-like body, and two pairs of large, elongated paddles. It comprises only one species. The skull of Plesiosaurus is much narrower than long, reaching its width just behind the eyes. It would grow to a length of about 3.5 meters. The first skeleton of Plesiosaurus was found in Sinemurian (Early Jurassic) age rocks of the lower Lias Group by early paleontologist and fossil hunter Mary Anning in December 1823. Additional fossils were discovered in the rocks of the Lias Group of Dorset. The species name, P. dolichodeirus, was described and named by Conybeare on the basis of Anning’s original finds, in 1824.
Phorusrhacids, or terror birds, are the large carnivorous flightless birds that were the largest species during the Cenozoic era in South America. Their living range covers from 62 to 1.8 million years ago. Phorusrhacids ranged from one to three meters tall. Their closest modern-day relatives are the 80 cm-tall seriemas. Titanis walleri is one of the largest species of Phorusrhacid, in North American from Florida and Texas. It is only known large South American predator to migrate north during the Great American Interchange. It was also believed that T. Walleri species became extinct in North America at the time of arrival of humans. There are reports of new findings in Uruguay dating to 450,000 and 17,000 years ago. They may have used their claws to tear apart carcasses and helping them tear flesh. The new fossil of Phorusrhacid has been described as about 3 meters tall. These large terror birds were quick runner and were able to reach speeds of 48 km/h.
Stegosaurus is a genus of armored dinosaur. The fossils of Stegosaurus have been found in the western United States and Portugal, in rocks dated to the Late Jurassic period, between 155 and 150 million years ago. Many species have been classified in the upper Morrison Formation. The remains of more than 80 individuals of this genus have been found. They would have lived alongside dinosaurs such as Diplodocus, Apatosaurus, Brachiosaurus, Ceratosaurus, and Allosaurus. These were a heavily built, herbivorous quadrupeds with short fore limbs, rounded backs; tails held high in the air and long hind limbs. It is one of the most recognized kinds of dinosaur due to a distinctive combination of broad, tail tipped with spikes and upright plates. An array of plates and spikes has been the subject of discussion among scientists. It is believed that their spikes were used for defense against predators, and their plates were used for display and thermoregulatory functions. A specimen, discovered in 1994 is 4.6 meters long and 2 meters high and is estimated to have weighed 2.4 metric tons while alive. The skeleton is on display at the University of Wyoming Geological Museum.
Entelodon is an extent genus of entelodont artiodactyl endemic to Eurasia. Its fossils are found in Paleogene strata ranging in age from the Houldjinian until the Reptilian epoch of the early Oligocene. It was a fairly entelodont, with large, bulky body, a long snout, and slender legs. It had complete autherian dentition. Entelodon had two toes on each foot, and its legs were helpful for fast running. It was around 1.35 meters tall at the shoulders, with a 65 cm skull. One remain are known from Europe, and one specimen was found as far as northern China. In Europe, remains of Entelodon were found in Germany, Spain, Romania, France, and the Caucasus. Most of the remains of Entelodon were discovered in Vayres-Sur-Essonne, France.
Mapusaurus was a giant carnosaurian dinosaur from the early Late Cretaceous of what is now Argentina. This dinosaur was similar in size to its relative Giganotosaurus, with the largest individuals estimated as about 10.2 meters in length and weighing three metric tons approximately. Mapusaurus was excavated by the Argentinian-Canadian Dinosaur project between 1997 and 2001, from an exposure of the Huincul Formation. It was described and named by Phil Currie and Rodolfo Coria in 2006. The fossil remains were discovered in a bone bed having at least seven individuals of different growth stage.
Spinosaurus is a genus of theropod dinosaur that lived in North Africa, about 112 to 97 million years ago during the lower Albian to lower Cenomanian stages of the Cretaceous period. The first time, the skeleton of Spinosaurus was discovered in 1912 in Egypt and described in 1915. However, the original skeleton was destroyed in WW II. Another fossil remains has been recovered from Morocco. It was among the largest of al carnivorous dinosaurs. According to 2005, 2007 and 2008 studies, Spinosaurus was between 12.6 to 18 meters in length and 7 to 20.9 tons in weight. The skull was long and narrow, similar to modern crocodilian. Some scientists suggest that it lived in water and on land as a modern crocodilian does. They hunted both aquatic and terrestrial prey. The distinctive spines of Spinosaurus grew to at least 1.65 meters long and were likely to have had skin connecting them to form a sail-like structure.
Carnotaurus is a genus of large theropod dinosaur that lived between about 72 and 69.9 million years age in South America during the Late Cretaceous period. The only species of Carnotaurus is Carnotaurus sastrei, known from a well-preserved skeleton. It is the best-understood theropods from the Southern Hemisphere. The skeleton was uncovered in 1984 in the Chubut Province of Argentina from rocks. It is the member of the Abelisauridae, a group of large theropods that covered the large predatorial niche in the southern Landmasses of Gondwana. Carnotaurus was a bipedal predator, measuring eight to nine meters in length and weighing 1.35 metric tons approximately. Carnotaurus had thick horns above the eyes and a deep skull sitting on a muscular neck. Further, it was characterized by vestigial forelimbs and slender hindlimbs. According to some studies, they were able to hunt down very large prey such as sauropods. It was well adapted for running and was one of the fastest large theropods.
Argentinosaurus is a genus of titanosaur sauropod dinosaur discovered in Argentina by Guillermo Heredia. This type of dinosaur lived on the then-island continent of South America between 94 and 97 million years ago. It is one of the largest known dinosaurs. The first fossils were found in 1987 by a rancher, who mistook the leg for a giant piece of petrified wood. The estimated length of Argentinosaurus was 30 to 35 meters, with a weight of up to 80 to 100 tons. The skeletal restoration mounted in Museo Carmen Funes is the longest reconstruction and comprises the original material. According to researchers, Argentinosaurus do not stop growing their whole lives. They would have had to grow 25,000 times their original size before reaching adult size. Young Argentinosaurus were vulnerable to attacks from predators. The eggs of Argentinosaurus were around 22 centimeters.
Pteranodon is a genus of pterosaurs which contained some of the largest flying reptiles having wingspans over 6 meters. Pteranodons existed during the late Cretaceous geological period of North America in present day Alabama, Kansas, Wyoming, Nebraska, and South Dakota. Highest fossil specimens of this species have been found than any other pterosaur, and many of them well preserved with complete skulls and articulated skeletons. Although, some scientists believed that Pteranodon was not a dinosaur. However, it is frequently featured in dinosaur media and associated with dinosaurs strongly by the general public. They are divided into two distinct size classes. Adult male Pteranodon were the largest pterosaurs and the largest flying animals before the 20th century. The male Pteranodon had a wingspan of 5.6 meters. Adult females were smaller with 3.8 meters wingspan. They had toothless beaks, similar to birds. They mostly feed on fish because fossilized fish bones have been found in the stomach area of Pteranodon skeleton.
Estemmenosuchus is a genus of large and early omnivorous therapsid. This dinosaur lived during the middle part of the Middle Permian approximately 267 million years ago. Two species of Estemmenosuchus are characterized by horn-like structures, probably used for intraspecific display. Both species are from the Perm region of Russia. Two other Estemmenosuchus, are now considered females of the species E. uralensis. It had a sprawling posture and could reach a body length of over 3 m. The skull of Estemmenosuchus was massive and long, up to 26 inches in length, possessed different sets of large horns, similar to the antlers of a moose. It had a sprawling posture as described by analyzing its shoulder joints. Two species were found from the Ezhove place near Ochyor in the Perm region of the Russia in 1960. Their skin appears to be smooth with no signs of either hairs or scales. Due to their skulls, it is assumed that they were the scariest dinosaurs at that time.
Rajasaurus is a genus of carnivorous abelisaurian theropod dinosaur. The fossilized bones of Rajasaurus were discovered between 1982 and 1984 by Suresh Srivastava of the Geological Survey of India. It was found from the Narmada River valley in the Kheda district of Gujrat, India. American and Indian scientist announced it as a new genus of a dinosaur on 13 August 2003. Rajasaurus was an abelisaurid, known to have lived only on landmasses that were part of supercontinent Gondwana including Madagascar, Africa, India, and South America. Rajasaurus is an island Dinosaur that had separated from the Indian landmass about 20 million years ago. Rajasaurus was identified from a skeleton including a part of the skull, hip bones, backbone, parts of the hind legs and tail. This species measured about 6.6 meters in length. It was one of the scariest dinosaurs of ancient times.