Where were the continents located during the Jurassic period?
In the Early Jurassic period the continents were still clustered around the equator roughly in the shape of a C that bordered the Tethys Sea. However, unlike the Triassic period, in which the continents were all part of one giant landmass known as Pangea, a split formed during the Jurassic period that divided Pangea into two large landmasses. The most accepted theory for the breakup of the supercontinent Pangea is the action of plate tectonics, causing a spreading rift split the C shape of Pangea into two large, separate landmasses.
Laurasia and Gondwana began to break up during the Jurassic period. The numbers indicate what would become 1) North America, 2) Eurasia, 3) South Amelia, 4) Africa, 5) the Indian subcontinent, 6) Antarctica, and 7) Australia.
What were Laurasia and Gondwana?
Laurasia and Gondwanaland, or Gondwana, were the two major continents (often called supercontinents) of the Jurassic period. As the gap between North America and Africa widened, driven by the spreading rift, so did the gap between North and South America. Water filled this gap, separating Pangea into the northern continent of Laurasia, and the southern continent of Gondwana. Despite the separation of the huge continent, scientists have found fossil skeletons of the Brachiosaurus and plated stegosaurs in Africa and North America. This indicates that although the continents were separating, there were probably land bridges that popped up from time to time, allowing the species to spread to both continents.
Laurasia included the present-day areas of Europe, North America, and Siberia. Also included in this large landmass was Greenland. Gondwana included the present day areas of Africa, South America, India, Antarctica, and Australia.
How did the northern continent of Laurasia and the southern continent of Gondwana change during the Jurassic period?
As the rift grew westward, separating Pangea into Laurasia and Gondwana, and millions of years passed, there were numerous changes on each of these large continents. Africa began to separate from Europe, starting the formation of the Mediterranean Sea. Italy, Greece, Turkey, and Iran were attached to the North African part of Gondwana, while Antarctica and Australia detached from Gondwana, but were still in contact with each other. And the block of land we now call India drifted northward.
North America separated from Gondwana and drifted west, resulting in the formation of the Gulf of Mexico, and the widening of the North Atlantic Ocean. South America and Africa began separating, creating a long, narrow seaway that would eventually become the South Atlantic Ocean. In addition, sea levels rose during this period, resulting in shallow seas flooding parts of North America and Europe in the late Jurassic.
Did climate conditions lead to new dinosaur groups in the Jurassic period?
Yes, scientists believe the climate turned milder in the Jurassic period and lush, tropical vegetation began to grow. This gave rise to new dinosaur groups, including the long-necked sauropods (plant-eaters). The increase in the amount of vegetation allowed these animals to grow quite large. Their long necks allowed these animals to reach food that was out-of-touch for most other dinosaurs. With abundant food supplies, these plant-eating animals continued to grow from generation to generation.
With a new climate permitting, larger plants were able to grow. As a result, dinosaurs like the long-necked sauropods evolved to reach them (iStock).