Crocodiles are large aquatic tetrapods that live throughout the tropics in Africa, Asia, the Americas and Australia. Crocodiles are archosaurs, which means they are genetically close to birds and dinosaurs. Crocodiles tend to live in freshwater habitats such as rivers, lakes, wetlands and brackish water. They feed mostly on fish, reptiles, and mammals depending on species. They first appeared about 55 million years ago.
Tyrannosaurus rex was one of the largest meat-eating dinosaurs that ever lived.
Everything about this ferocious predator, from its thick, heavy skull to its 4-foot-long (1.2-meter-long) jaw, was designed for maximum bone-crushing action. Fossil evidence shows that Tyrannosaurus was about 40 feet (12 meters) long and about 15 to 20 feet (4.6 to 6 meters) tall. Its strong thighs and long, powerful tail helped it move quickly, and its massive 5-foot-long (1.5-meter-long) skull could bore into prey.
Utahraptor was a large, terrifying mid-Cretaceous predator with 9-15 inch long middle-toe claws. It was a lightly built, fast-moving, agile, bipedal (walked on two legs), bird-like dinosaur. It had a curved, flexible neck and a big head. Sharp, serrated teeth were set into very powerful jaws. Each of its three fingers on each arm had large, sharp, curved claw.
It had four-toed feet; the second toe had a 9-15 inch sickle-like claw and the other toes had smaller claws. Its long tail had bony rods running along the spine giving it rigidity; the tail was used for balance and fast turning ability. It had a relatively large brain and large, keen, eyes. Utahraptor was 16-23 feet long and may have weighed about 1 tonne.
The Komodo Dragon is the largest living species of lizard, growing to a maximum length of 3 metres in rare cases and weighing up to around 70 kg. As the dominant predators on the handful of islands they inhabit, they will eat almost anything, including carrion, deer, pigs, smaller dragons, and even large water buffalo and humans. When hunting, Komodo dragons rely on camouflage and patience, lying in wait for passing prey. When a victim ambles by, the dragon springs, using its powerful legs, sharp claws and serrated, shark-like teeth to eviscerate its prey.
Deinonychus was a lightly built, fast-moving, agile, bipedal (walked on two legs), bird-like dinosaur. It was built to kill. This meat-eater had a curved, flexible neck and a big head with sharp, serrated teeth in very powerful jaws. Each of its three fingers on each hand had large, sharp, curved claws. It had four-toed feet; the second toe had a 5-inch sickle-like claw, and the other toes had smaller claws. Its long tail had bony rods running along the spine, giving it rigidity; the tail was used for balance and fast turning ability. Deinonychus had a relatively large brain and large, keen eyes. Deinonychus was about 10 feet long, 5 feet tall, and weighed up to 80 kg.
Stegosaurus was a plant eater. It had a very small head with a tiny brain and toothless beak, large, flat, bony, triangular plates along its back and a heavy, spiked tail for protection. It walked on four legs, but the back legs were twice as long as its front legs. Stegosaurus weighed 3 tonnes and was roughly 9 metres long.
Pentaceratops was a rhinoceros-like dinosaur. It walked on four sturdy legs and had three horns on its face along with a large bony plate projecting from the back of its skull (a frill). One upward-pointing horn above its parrot-like beak and two longer, forward-pointing horns above its eyes probably provided protection from predators, and were possibly used in mating rivalry and rituals. It also had two enlarged, horn-like cheekbones that protruded from its face. It had a very large skull, 9.8 feet long, with a very large, bony, scalloped, head frill. It has the largest-known skull ever found for a land-dwelling animal.
Parasaurolophus was a long-crested, duck-billed dinosaur. Parasaurolophus grew to be about 40 ft (12 m) long and 8 feet (2.8 m) tall at the hips. It weighed about 2 tons. It had pebbly-textured skin, a spoon-shaped beak, and a pointy tail. It may have had webbed fingers, giving it a mitten-like hand. Its sight and hearing were keen, but it had no natural defenses. It had a toothless, horny beak and numerous cheek teeth.
Velociraptor was a small carnivorous dinosaur. It had a sharp, deadly, sickle-shaped, retractible, 3.5 inch (9 cm) long claw on each foot Velociraptor may have been able to run up to roughly 40 mph for short bursts. This predator may have hunted in packs.
Spinosaurus may have been the largest meat-eater to walk the Earth. At a jaw-dropping 17m long and weighing up to 20 tonnes, it was even larger than the mighty Tyrannosaurus. Spinosaurus’ sail may have been for heat dissipation - it lived in a swampy environment near the equator during the warm Cretaceous period. The sail may have also been used to attract mates or seem bigger than it was.
Postosuchus was a fierce predator. It had long pointed teeth typical of carnivorous reptiles. Postosuchus walked on all four limbs. Rows of small bony plates in the skin of Postosuchus lined the backbone and protected it from predators. After Postosuchus became extinct, carnivorous dinosaurs became much bigger and came to dominate every continent. It was 6 metres long and weighed up to 300kg.
With its rock-hard horns, shield like head plate, and massive torso, Triceratops must have been an intimidating presence in the late Cretaceous period. But this giant was an herbivore, eating only vegetation of western North America.
Triceratops was roughly 9 metres long and weighed 6 - 12 tonnes.
When threatened by predators, Triceratops probably charged into its enemy like the modern-day rhinoceros does. Triceratops was probably a herding animal, like the other ceratopsians. T-Rex probably ate dinosaurs like Triceratops.
The Brachiosaurus was a huge dinosaur that ate between 200 and 400 kilograms (440 and 880 pounds) of plants every day!
It had a relatively small tail compared to other Sauropods, reached around 26 metres (85 feet) in length and even had an asteroid named after it. The weight of Brachiosaurus has been estimated between 30 and 45 metric tons.
Apatosaurus ( Deceptive Lizard)
Plant Eater, 21-27 Metres long.Lived 157 - 146 million years ago.
Weight 30-35 Tonnes.
Apatosaurus swallowed stones to help grind up its tough plant food. It did not chew its food.
Apatosaurus' nostrils were located on the top of its head.
Fossils have been found in Colorado,Oklahoma,Utah and Wyoming in the USA.
Pteranodons were flying reptiles that were about 6 feet long, had a 25-33 foot wingspread, and weighed about 25kg; its standing height was about 6 feet. This wing-span is longer than any known bird. Pteranodons had hollow bones, were lightly built, had almost no tail, and small bodies; they may have had fur. They had large brains and good eyesight. Some pteranodons had long, light-weight, bony crests on their heads that may have acted as a rudder or stabilizer when flying, or may have been a sexual characteristic. They had no teeth. Pteranodon wings were covered by a leathery membrane. This thin but tough membrane stretched between its body, the top of its legs and its elongated fourth fingers, forming the structure of the wing. Claws protruded from the other fingers.
Dromaeosaurus was a small, fast-moving predator. This dinosaur had sharp teeth, big eyes, and a deadly, sickle-like claw on each foot. It was a relatively small dinosaur at only 1.8 metres long and weighed only 15 kg.
Dimetrodon was not a dinosaur, but a pelycosaur, a so-called mammal-like reptile. The pelycosaurs led to the mammals; they are more closely related to us than to the dinosaurs. Dimetrodon had sharp teeth and clawed feet and a sail-like flap of skin along its back. Dimetrodon was a Meat Eater, was 3.5 metres long and lived 280-245 million years ago.