Jurassic Period – Biological Changes :

The cycads , but conifers, ginkgos, palms, horsetails dominated the plant life of the Jurassic period, and ferns were also abundant, conifers and pines, mixed with tree ferns and ginkgos, populated the forests . the ground was covered with ferns and cycads.

First bird like reptile (Archaeopteryx) appears. primitive mammals make their first appearance .they were few and small, but continue to develop and become well established during the period.

Of the Marine invertebrates the most important were the ammonites. More than 1000 species of insects could be found , including many of the modern forms. the Dominant animals on land , in the sea and in the air were the reptiles. Dinosaurs more numerous and more extra ordinary, crocodiles , Ichthyosaurus, and Plesiosaurus ruled the seal while the pterosaur and their relatives inhabited the Air.