into Hindi
26 Nov 2014 12:50
26 Nov 2014 12:50
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26 Nov 2014 12:50
Dinosaurs are a diverse group of
animals of the clade Dinosauria.
They first appeared during the
Triassic period, 231.4 million
years ago, and were the dominant
terrestrial vertebrates for 135
million years, from the beginning
of the Jurassic (about 201 million
years ago) until the end of the
Cretaceous (66 million years ago)
, when the Cretaceous–Paleogene
extinction event
led to the extinction of most
dinosaur groups at the close of
the Mesozoic Era. The fossil
record indicates that birds
evolved from theropod dinosaurs
during the Jurassic Period and,
consequently, they are considered a subgroup of dinosaurs by many paleontologists.