The Dinosaur Extinction Mystery
By Michael Bento
EES 112-25; Fall 2016
One of the great unsolved mysteries in our planet’s history is the extinction of dinosaurs. We know they existed through fossil record and with the help of some geological evidence that supports various theories, some stronger than others, we start to narrow down the possible culprit. Dinosaurs evolved and existed for about 180 million years during the Mesozoic era. The Mesozoic is divided into three periods: the Triassic, Jurassic, and Cretaceous periods. They thrived in the Triassic and Jurassic periods, but declined in the Cretaceous period. The Triassic period lasted about 245 to 213 million years ago where dinosaurs first evolved and all the continents were still connected, better known as Pangaea. The Jurassic period continued to the beginning of the Cretaceous period 144 million years ago. At this time, the continents started to break apart and dinosaurs increased in number. The Cretaceous period was the last period in the Mesozoic era and at the end of the period, some 65 million years ago, dinosaurs disappeared known as the K-T extinction event. We know this because fossils were found throughout the Mesozoic era, but not in Cenozoic era rock layers. Birds and other reptiles such as alligators survived into the Cenozoic era, better known as the Age of Mammals (Barrett & Raul, 2001).
The first dinosaur skeletons were found in England around the 1820’s and by 1889, there were samples