Scientists first started studying dinosaurs during the 1820’s, when they discovered the bones of the biggest land reptile they named a Megalosaurus (“big lizard”) buried in the English countryside. In 1842, Sir Richard Owen, top paleontologist of Britain, first introduced the term “dinosaur.”Everyone knows that dinosaurs were really big, that some of them had feathers, and that they all went extinct 65 million years ago after a giant meteor hit the earth.They lived on the planet during a period called the Mesozoic Era. They also lived during the Triassic, Jurassic and Cretaceous periods as well.
It is widely agreed upon by the scientific community that many dinosaurs almost certainly evolved into birds. Dinosaurs evolving into birds actually happened a few times throughout history, and it wasn’t always successful. A prime example of this is the feathered Microraptor that has no living descendants. Well-preserved fossils have shown clear evidence of feathers appearing on a number of raptor species.
Dinosaurs were once thought to be the cold-blooded kings of the Mesozoic era. But new research on their growth rates suggests the prehistoric beasts grew just as fast as mammals, indicating they were warm-blooded creatures. Modern reptiles like turtles and crocodiles are cold-blooded, or “ectothermic,” meaning they need to rely on the external environment to maintain their internal body temperatures–while modern mammals and birds are warm-blooded, or “endothermic,” possessing active, heat-producing metabolisms that maintain a constant internal body temperature, no matter the external conditions. There’s a solid case to be made that at least some meat-eating dinosaurs–and even a few ornithopods–must have been endothermic, since it’s hard to imagine such an active lifestyle being fueled by a cold-blooded metabolism. (On the other hand, it’s unlikely that giant dinosaurs like Argentinosaurus were warm-blooded since they would have cooked themselves from the inside out in a matter of hours.)
What is the smallest dinosaur? Not all dinosaurs were giants! In this article we try to find out what was the world’s smallest dinosaur. The smallest fully-grown fossil dinosaur is the little bird-hipped plant-eater like lesothosaurus, which was only the size of a chicken. Smaller fossilised examples have been found, but these are of baby dinosaurs. Lesothosaurus was a herbivore. It lived in the Jurassic period and inhabited Africa.
The most brainy Dinosaur was Troodon. Troodon was a omnivore. It lived in the Cretaceous period and inhabited Asia and North America. The Troodon had a large brain for its relatively small size and was probably among the smartest dinosaurs. Its brain is proportionally larger than those found in living reptiles, so the animal may have been as intelligent as modern birds, which are more similar in brain size.
What killed the dinosaurs? Dinosaurs roamed the Earth for 135 million years. Filling every ecological niche, from the oceans, forests and plains; even the skies. Then, 66 million years ago, something terrible happened. In a geological instant, 75% of the plants and animals on Earth went extinct. And all of the land dinosaurs were wiped off the Earth forever. It is believed that dinosaur extinction was part of a mass extinction brought about by two massive destructive events. The first of these was the collision with the Earth of a meteorite landing in what is now the Yucatan Peninsula, of Mexico. This was followed by an enormous volcanic eruption which split what is now India in half.
Word ‘dinosaur’ means ‘terrible lizard’, and comes from the Greek words dino (meaning ‘terrible’) and saur (meaning ‘lizard’). When scientists first discovered dinosaur fossils, they imagined them to be the remains of huge lizards from the past. That’s not a nice way to call someone, by the way.
The largest land animal ever found, Argentinosaurus evolved in the Cretaceous Period and belongs to a family that originated in the southern continents of Gondwana (an ancient supercontinent). The massive herbivore’s body weight was equal to a little more than a dozen, full grown elephants. Named for the nation of Argentina where it was discovered, Argentinosaurus is among the largest verifiable genera of dinosaur ever known. Active during the late Cretaceous, this enormous creature may have been over 100 feet long and weighed more than 80 tons.
Not all Dinosaurs extinct at the same time. When that meteor impacted the Yucatan Peninsula, 65 million years ago, the result wasn’t a huge fireball that instantly incinerated all of the dinosaurs on earth (along with their cousins described in the previous slide, the pterosaurs, and marine reptiles). Rather, the process of extinction dragged on for hundreds, and possibly thousands, of years, as plunging global temperatures, lack of sunlight, and the resulting lack of vegetation profoundly altered the food chain from the bottom up. Some isolated dinosaur populations, sequestered in remote corners of the world, may have survived slightly longer than their brethren, but it’s a sure fact that they aren’t still alive today!
Dinosaurs lived during a time of Earth’s history called the Mesozoic. The Mesozoic Era is the age of the dinosaurs and lasted almost 180 million years from approximately 250 to 65 million years ago. This era includes 3 well known periods called the Triassic, Jurassic, and Cretaceous periods. Earth’s climate during the Mesozoic Era was generally warm, and there was less difference in temperature between equatorial and polar latitudes than there is today. The Mesozoic was a time of geologic and biological transition. During this era the continents began to move into their present-day configurations.
The earliest named dinosaur found so far is the Eoraptor, which means “dawn stealer.” It was named this because it lived at the dawn of the Dinosaur Age. It was a meat eater about the size of a German shepherd. Eoraptor is a dinosaur which lived approximately 228 million years ago during the late Triassic Period. It was first discovered in 1991 by Ricardo Martinez in Argentina, South America.