History of B.C.
The Early Dinosaurs
During the Triassic period, Pangaea was at its largest. The climate was much the same as that of the Permian period, warm and dry. Middle-sized, mammal-like reptiles dominated the beginning of this period, but early dinosaurs took over in the last ten to fifteen million years of the Triassic. Unlike amphibians, these reptiles supported their weight on strong legs, rather than dragging themselves along the ground, and quickly evolved into both herbivores and carnivores. Mammals arose during this time also, but were only small, shrew-like animals. The first crocodiles, frogs, and turtles are also known in this period, and ceratites and ichthyosaurs lived in its warm oceans.
In the Jurassic period, Pangaea split apart into Laurasia (of which British Columbia is now a part of) and Gondwana, and the breaking away of Greenland led to the early Atlantic Ocean. Most of British Columbia was still underwater, but a strip of land ran through western Canada and down into the United States, as plate tectonics continued to push it northward. During this period, the world's average temperature was between 21°C and 27 °C, making the climate constantly mild and pleasant, with the same groups of dinosaurs and plants living on all continents. Plant-eating dinosaurs evolved into the largest land creatures that ever lived, while some small carnivorous dinosaurs developed feathers and became the ancestors of birds, some 165 million years ago. Ichthyosaurs and plesiosaurs ruled in the seas, and ammonites (cephalopods) were in abundance.
History of B.C.
|back to top|