Dinosaurs were animals that
ranged in form from reptile-
like to bird-like. Dinosaurs
dominated the world for over
160 million years, first
appearing approximately 230
million years ago. 65 million
years ago, all non-avian
dinosaurs became extinct.
Dinosaurs still exist today in
the line of birds (avian
dinosaurs). The first dinosaur
was recognized in the 19th
century, and the
term "dinosaur" was formally
named by the scientist
Richard Owen in 1842. The
name is derived from the
Greek words deinos ("terrible"
or "fearfully great") and
sauros ("lizard" or "reptile").
