They ruled the Earth for 160 million years1.The name "dinosaur" comes from Old Greek "deinos" ("terrible") and "saurus" ("lizard"), and was advanced by Richard Owen in 1841. The dinosaurs emerged at the end of the Triassic, about 225 million years ago, from a group of reptiles called Archosauria. Archosauria was a sister group to lizards and they gave birth both to dinosaurs and crocodiles.
Eryhtrosuchus was a typical archosaur. The main trait of these reptiles was their vertically positioned limbs, not in a lateral configuration, like in the lizards nowadays. This way, they could make larger steps with less energy, unlike crawling reptiles, being more rapid and efficient at the same time. In time, they developed bipedalism (walking on two feet) and from this group, both dinosaurs and crocodiles evolved.
Another important evolutionary achievement of the archosaurs was a changed architecture in the bones of the mouth roof that allowed them to breathe and eat at the same time.
Dinosaurs ruled the Earth for 160 million years before disappearing 65 million years ago. Dinosaur fossils were found all the time, but the first described dinosaur is Iguanodon, a relative of the duck billed dinosaurs. The description was made in 1822 by Gideon Mantell.
2.The largest dinosaurs were the sauropods, the long legged, long tailed giant herbivorous type. The Argentinosaurus could have weighed 90 to 110 tons (as much as 16 African elephants) while the Supersaurus could have been 40 m (130 ft) long (longer than the blue whale). These dinosaurs consumed about one ton of food daily and swallowed boulders to chew the food inside their stomachs.
The heads were elongated and light, and the neck was rather stiff, thus the animal fed on the lower vegetation, like a vacuum cleaner, not from the tree top. The lips were thick and muscled like those of the moose, not thin and narrow like in other reptiles. These lips enabled the giants to swallow huge amounts of food. These lips were betrayed by the huge nerve orifices going through the maxillaries. The tail was muscular and they could have used the tail and the rear limbs as tripods, raising the fore body for reaching the tree tops.
The pelvis was the largest in the animal world. Over half of the tail was very thin, and the tail could have been used like a defensive whip which reached speeds of 1,150 km (750 mi) per hour! A 77 -ton sauropod could have eaten the food ingested by four large elephants, and an individual may have required over 120 hectares for feeding. The stomach could have had a capacity of 10 tonnes and they swallowed stones for grinding the food that was digested with the help of gut bacteria.
The heart of these dinosaurs head to make enormous efforts to pump large amounts of blood in such long necks to the brain. The pressure required to pump blood at a distance of 3-4 m (10-13 ft) would have burst the blood vessels. It seems that these animals kept their heads rather tilted (not vertical like in giraffes), so that the heart did not have to pump blood against the gravitation.
Some believe that the long necks and tails were meant to release the huge amount of heat produced by such gigantic organisms.
3.Many herbivorous dinosaurs formed herds and, like in elephants today, the young ones were placed in the middle of the group, for protection.
Triceratops and related species had rhinoceros-like horns for defense, while the ankylosaur dinosaurs were covered by bony plates and hit their enemies with the tail, ended into a bony club. The Stegosaurus had bony plates on its back and the tail ended in dagger-like long bony spines, for defense.
It may have resemble a rhino, but Triceratops was 9 m (30 ft) long, 2.5 m (8.3 ft) tall and weighed 7 tonnes, as much as 5 black rhinos.
The Pachycephalosaurus had a large, bony dome atop its skull, 25 cm (10 in) thick, which safely cushioned its tiny brain, pointing the males could have clashed head to head, like modern wild rams, during the mating season while competing for females.
4.When you think about something huge that has caused terror on earth, the T-rex is perhaps the first thing that comes to your mind. Indeed, a huge beast: up to 12.8 (42 ft) in length and 7.2 tones in weight. Bigger than an elephant! The teeth were 16 cm (6.4 inches) long, more than twice the size of a lion's or tiger's canines. The bite force was calculated to 1,350 kg power, 10 times more powerful than that of a Great White Shark. The mouth could open up to 70 cm (2.3 ft), and the beast could swallow 20-30 kg (44-66 pounds) of meat at once.
For 150 years, T-rex has been regarded as the giant of the carnivore dinosaurs. Then, in 1993, a longer carnivore dinosaur was found in Argentine: Giganotosaurus, which was up to 13.2 m (44 ft) long.
But the largest carnivore dinosaur (and land carnivore in general) to have ever existed was in fact the Spinosaurus, whose remains were first discovered in 1910. It lived in nowadays North Africa during the Cretaceous Period, 95 to 93 million years ago.
The Spinosaurus had specific "spines" on the back, long extensions of the vertebrae - up to 2 m (6.6 ft) long, and could have formed a sail-like structure or a hump. The Spinosaurus reached a length of up to 18 m (59.1 ft) and was up to 9 tones (but the numbers are still disputed).
It had a body much slender than the T-rex's and the head was more like that of a crocodile, fact that made some scientists think this dinosaur was a fisher, while others believe it was a scavenger.
5.Smaller carnivorous dinosaurs are believed to have run with 50 km (30 mi) per hour, the speed of a race horse, while the sauropods are believed to have moved with the velocity of an elephant (their feet too were similar to an elephant's). The largest sauropods could have had a speed of 4 km (2.5 mi) per hour.
The velociraptor, the speedy and ferocious star from "Jurassic Park," could speed up to 24 mph (38 kilometers per hour), while the 6 tones T-rex, "only" 18 mph (29 kilometers per hour). An elite human sprinter cannot run faster than 25 mph (40 kilometers per hour).
Deinonychus, a small carnivorous dinosaur, seemed to hunt in groups and used a large retractile claw to tear the flash of its prey.
One of the smallest dinosaurs, the Compsognathus, 6.6 pound (3 kg) heavy, with roughly 40 mph (64 km per hour), could outrun an ostrich, the fastest living modern bipedal animal, with 5 mph (8 km per hour).
6.The dinosaurs made nests and took care of their young the way birds do today, or at least protected them. Birds are, in fact, the closest living relatives of the dinosaurs, being evolved from these reptiles.
The largest dinosaur egg ever found was 30 cm (1 ft) in length and belonged to the Hypselosaurus.
6.The Stegosaurus was 6 m (20 ft) long and weighed 2 tons. Its brain was just the size of a walnut! To compensate this, the spine presented a second "brain" in the pelvic area.
The Troodon was a feathered dinosaur from the Late Cretaceous Period (75-65 mya) of North America. It was 2 m (6.5 ft) long, 1 m (3 ft) tall, and weighed 60 kg (130 lb). It had large, retractable sickle-shaped claws on its second toes, which it would raise off the ground when running.
The Troodon possessed one of the relatively largest known brains the dinosaurs had, comparable to that of modern birds, that's why it's regarded as the most intelligent dinosaur. Many speculate that if dinosaurs had not disappeared, the Troodon could have evolved in a highly intelligent creature like humans, the dinsauroid.
7.In our minds, the word "dinosaur" is synonymous to huge. But not all the dinosaurs were enormous beasts. The Shanag, found in Mongolia, was about the size of a crow.
8. The huge T-rex could have had feathers! A primitive species from its family (Tyrannosauridae), found in China, Dilong paradoxus, was covered by primitive feathers.
But skin impressions from adult tyrannosaurids in Canada and Mongolia reveal pebbly scales, like in other dinosaurs. Now, researchers believe that, like in super-sized mammals (elephants, hippopotamus, and rhinoceros), adults lost feathers as they retained too much heat. The Cretaceous climate, that is when the T-rex lived, was indeed hot. Perhaps adult T-rexes still had feathers just on some body parts.
9. The Microraptor was a four-winged dinosaur, weighing one kilogram, aged 125 million years, which lived in the territory of today's China. This dinosaur used the two upper wings as well as two lower wings in an aerodynamic design similar to the biplanes of the early XXth century. Scientists believe that the first birds, too, flew using four wings, like Microraptor, but the pattern proved ineffective and abandoned during the evolution. Pedopenna, another dinosaur, presented a similar flight.
10. The Bambiraptor was a 75-million year old carnivorous feathered dinosaur roaming through North America. It was small, like most bird-like dinosaurs: less than 0.3 meters (1 ft) off the ground, 0.7 meters (2.3 ft) in length, and a 2 kilograms (4.4 lbs) weight.
The Bambiraptor had opposable fingers 75 million years ago, 15 millions years before the most primitive primates developed opposable thumbs. Bone models showed that Bambiraptor would have been able to grip prey with both arms, or employ its long arms to bring objects to its mouth.
The minute dinosaur could have positioned the tips of the outer two of its three fingers together, the way a human can touch the tip of the thumb with the tip of the middle finger. The Bambiraptor surely had long feathers on its arms, which could have interfered with the use of its hands, but maybe the hands extended beyond the feathers.
11.Dinosaurs prove the theory of the continental movement. For example, Majungatholus atopus, a 9 m (30 ft) long carnivorous dinosaur, with a forehead horn and pneumatic nasal fossae that lived in Madagascar 70-65 MA years ago resembles the contemporaneous Majungasarus from India bu also Carnotaurus sastrei from Argentina! This shows that 80 MA years ago, the tree land masses were still part of Gondwana supercontinent, while Africa could have already split around 100 MA ago.
12.The dinosaur Masiakasaurus knopfleri, found in Madagascar and measuring 2 m (6.6 ft) in length, got its name from Mark Knopfler, leader of the Dire Straits rock band, whose fun was its discoverer. The odd teeth of this dinosaur point it was a fish or insect eater.