The World of Dinosaurs
The Jurassic Period
The Jurassic period was the middle period of the Mesozoic era. The name Jurassic comes from
the Jura Mountains between France and Switzerland where the rocks formed during this period
were first studied.
Temperatures rose under the middle of the giant continent Pangaea causing tectonic forces
to break it up. The climate of the Jurassic was warm and humid, the polar regions were free
of ice, sea levels were higher, forests of conifers and ferns began to develop, birds began
to evolve from theropod dinosaurs.
In the early Jurassic the size of the dinosaurs increased steadily and eventually,
towards the middle of the Jurassic period, sauropods began to appear. These
animals grew to huge sizes and thrived well into the early Cretaceous period.
Giant marine reptiles such as dolphin like Ichthyosaurs, long necked Plesiosaurs and short necked
Pliosaurs started appearing in the seas. These marine reptiles developed through the Triassic and
into the Jurassic. Pliosaurs like Lipleurodon were major predators in the Jurassic seas whilst
Plesiosaurs tended to eat smaller fish and other small animals.
Flying reptiles, such as Pterodons, appeared in the late Jurassic.
