Division of Mesozoic era (II)

Jurassic Period

The second period was the Jurassic period (208-146 million years ago). In mid-Jurassic, Pangaea began to break apart, into Laurasia and Gondwanaland. The temperature was hot and dry, with strong seasonality at first, changing to warm and moist with no polar ice and vast flooded areas. More dinosaurs began to flourish, including gigantic ones, which roamed the earth, and pterosaurs flew. Archaeopteryx, the first primitive dinosaur-like bird also developed during the Jurassic period. Giant sauropods appeared along with many other dinosaurs. Also, the first primitive birds and flowering plants (angiosperms) appeared.

Cretaceous Period

The third Mesozoic period was the Cretaceous period (146-65 million years ago). The Continental drift which started from the Jurassic period continued at a faster pace, with accompanying volcanic activity. The continents almost had their modern-day look. Temperatures were warm, seasonality was low, and global sea levels were high (no polar ice!) at the beginning of the Cretaceous. Later, sea levels dropped, seasonality increased, and there were greater extremes in temperature between the poles and the equator. Dinosaurs flourish. Flowering plants (angiosperms) spread, displacing conifers and others. The oldest-known ants, snakes, and butterflies arose towards the end of the Mesozoic Era. A major extinction occurred at the end of the Mesozoic, 65 million years ago the extinction and demise of the dinosaurs and many other prehistoric animals.