Spanning more than 50 million years, the Jurassic period was marked by giant plant-eating dinosaurs feeding on lots of lush ferns and palm-like cycads. Dramatic climate change resulted in spectacular adaptations which included the rise of mammals and birds. The oceans were full of life too, as icthyosaurs, plesiosaurs, and giant crocodiles survived and thrived in warm seas.
High temperatures and humidity during the Jurassic period gave rise to an explosion of plant life and resulted in some of the largest animals the earth has known. As the vegetation grew thicker and taller, some dinosaurs followed suit. Enormous, long-necked sauropods such as diplodocus were true eating machines that gobbled up hundreds of pounds of plants each day and grew bigger than 75 feet long and 60 feet tall!
Although dinosaurs certainly ruled the Jurassic, small, furry animals were beginning to scurry around in the lush vegetation and scampering up trees. Because of their small size and mostly insect diet, humongous dinosaurs mostly left these tiny early critters alone. Because they had little competition , these mouse-sized mammals could sneak through the Jurassic and later the Cretaceous period and eventually dominate the planet.
Abundant plant life during the Jurassic period supported the lives of hundreds of thousands of hungry dinosaurs. Many Jurassic plants exist today and have remained unchanged for millions of years. Cycads resemble palm trees with thick trunks and a crown of fan-like leaves. Today, cycads are hardy trees and can thrive in a variety of habitats including deserts, swampy bogs, shaded areas, sunny areas, salt rich areas and even on rocky surfaces. Adaptation to diverse environmental conditions is probably what has allowed them to exist for so long. Many plant-eating dinosaurs fed on cycads.