BLOG #4 - DINOSAURS: CELEBRITIES OF EXTINCTION

Dinosaurs dominated life on Earth for some 180 million years from their beginning in the Triassic period 200 million years ago until their abrupt exit during the cretaceous period, more than 65 million years ago. They flourished during the Jurassic period when there were only two basic continents, but by the beginning of the cretaceous period 145 million years ago, they habitated the seven continent planet - albeit a warmer and better one with many species, both plants and animals, were gigantic.
               Based on the evidence studied by the paleontologists, dinosaurs fell into two basic physiological categories: those with bird hips and those with lizard hips, determined by the angle at which the pelvis was titled. Most had long tails; most laid eggs. Dinosaurs could be either carnivorous or herbivorous. Little is known about their temperature regulating mechanism. 

 A Velociraptor 

Plateoraptors

               A catastrophic event occurred at the end of the Cretaceous period, believed to be a giant asteroid that hit the Yucatan peninsula and formed the Chicxulub crater, still recognizable till today. Such an event would have caused  huge environmental changes leading to mass extinctions. Yet, dinosaurs seem to have been on decline for 20 million years before that. In any case, by the beginning of the cenozoic era, about 65.5 million years ago, dinosaurs were history.

A T-Rex Dinosaur