The traveling in flocks. Dinosaurs were the most popular

The earliest known description of dinosaur bones
is from China in 3000 BCE. Chinese apothecaries thought dinosaur bones that
were to be the bones of dragons. In 1842, Richard Owen coined the word “dinosaur”
which meant “terrible lizard”.

            Up
until the 1960s, dinosaurs were generally treated as sluggish, stupid creatures.
In 1964, the pivotal fossil discovery was the original sickle-clawed “raptor”
theropod, Deinonychus. It was discovered by Yale paleontologist John Ostrom. He
argued that some dinosaurs were truly more active than previous assumptions. Furthermore,
John Ostrom also noted many bird-like features on the skeleton of Deinonychus
and other theropod dinosaurs. It gave people the brand new idea that birds
evolved from a group of dinosaurs. Thus, this idea leads to a tendency to think
dinosaurs were more bird-like than lizard-like, such as looking after their
infants and traveling in flocks.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Dinosaurs were the most
popular organisms during the Mesozoic Era (225-65
million years ago). Dinosaurs existed for about 150 million years, and they dominated
every type of environment on Earth. They were land-dwelling vertebrates, and
members of the group Archosauria, a group of animals that also includes
pterosaurs (flying reptiles) and crocodiles. Dinosaurs can be classified by
their mode of eating. The Herbivore dinosaurs eat
plants, the carnivore dinosaurs eat meat, and the omnivore dinosaurs eat both
plants and meat.

The size range of Dinosaurs
are very broad. Little dinosaurs can be as small as 3 feet and weigh nearly 4 pounds, such as Compsognathus (small, bipedal, and carnivorous
dinosaurs). Big dinosaurs can be as large as over 100 feet long, and weigh up
to 150 tons, such as Brachiosaurus (long neck, small head, huge size, and herbivore
dinosaurs).

According to their hip
bones, dinosaurs are divided into two major groups. The first major group is
Saurischia (lizard-hipped dinosaurs). Saurischia can be further subdivided into
two smaller groups, the theropods (bipedal carnivorous dinosaurs), and the
sauropods (large, four-legged, herbivorous dinosaurs). The second major group
is Ornithischia (bird-hipped dinosaurus). Ornithischia can be further
subdivided into five smaller groups, the Ornithopoda (duck-billed dinosaurs),
the Stegosauria (plated dinosaurs), the Ankylosauria (armored dinosaurs), the
Pachycephalosauria (dome-headed dinosaurs), and the Ceratopsia (horned
dinosaurs).

            Dinosaurs
were living on earth during the Mesozoic Era, and it
was the “Age of Dinosaurs”. The word of Mesozoic means “middle life.”
The Mesozoic Era can be divided into three major periods: the
Triassic (248-206 million years ago), the Jurassic (206-144 million years ago),
and the Cretaceous (144-65 million years ago). First, dinosaurs appeared and evolved
in the Triassic period. Second, dinosaurs became diverse in the Jurassic period.
Last, dinosaurs became extinct at the end of the Cretaceous period. Each period
had various well-known forms. For example, the Triassic period had Eoraptor, Lessemsaurus,
and Pterosaurs. The Jurassic period had Allosaurus, Stegosaurus, and
Apatosaurus. The Cretaceous period had Tyrannosaurus, Velociraptor,
Triceratops, and Pachycephalosaurus.

            In
conclusion, dinosaurs are the most celebrated fossil organisms in the world.
These remarkably diverse and successful animals inhabited every major
continent, persisted over 150 million years, and evolved numerous bizarre forms
of varying body sizes.