| Dinosaurs
Size of a human compared to
a Tyrannosaurus rex.
Alligators have existed unchanged
for the past 65 million years. They are the last
remnants of the dinosaur age.
Dinosaurs, also known as dinos,
were vertebrate animals that dominated the terrestrial
ecosystem for over 160 million years, first appearing
approximately 230 million years ago. At the end
of the Cretaceous period 65 million years ago,
dinosaurs suffered a catastrophic extinction,
which ended their dominance on land. Modern birds
are considered to be the direct descendants of
theropod dinosaurs.
Since the first dinosaur was recognized in the
19th century, their mounted, fossilized skeletons
have become major attractions at museums around
the world. Dinosaurs have become a part of world
culture and remain consistently popular, especially
among children. They have been featured in best-selling
books and blockbuster films such as Jurassic Park,
and new discoveries are regularly covered by the
media.
The term dinosaur is also used informally to
describe any prehistoric reptile, such as the
pelycosaur Dimetrodon, the winged pterosaurs,
and the aquatic ichthyosaurs, plesiosaurs, and
mosasaurs, though none of these are technically
dinosaurs.
source: wikipedia.org |
