Three of the five largest mass extinctions in Earth history are associated with the Mesozoic: a mass extinction occurred at the boundary between the Mesozoic and the preceding Paleozoic; another occurred within the Mesozoic at the end of the Triassic Period; and a third occurred at the boundary between the Mesozoic and subsequent Cenozoic, resulting in the demise of the dinosaurs.rifting during the Late Triassic.

This separated Pangea into the continents of Laurasia and Gondwana.

During this era the continents began to move into their present-day configurations.

The Central Atlantic Magmatic Province, a huge volume of basalt, was created at the end of the Triassic during the initial rifting of Pangea.

The surface area of this igneous province originally covered more than 7 million square km (about 3 million square miles), and its rocks can be found today from Brazil to France.

For example, the northwesterly movement of North America resulted in a collision of the western edge of the North American continental plate with a complex of island arcs during the Late Jurassic.

So-called exotic terranes, geologic fragments that differ markedly in stratigraphy, paleomagnetism, and paleontology from adjoining continental crust, were accreted to the margin of the North American plate.

Some scientists have suggested that both of these large igneous events may have injected significant amounts of carbon dioxide and aerosols into the atmosphere, triggering a change in global climate.

The timing of these volcanic events appears to overlap the Triassic-Jurassic and Cretaceous-Tertiary, or Cretaceous-Paleogene, mass extinctions, and they may have played a role in them.The fauna and flora of the Mesozoic were distinctly different from those of the Paleozoic, the largest mass extinction in Earth history having occurred at the boundary of the two eras, when some 90 percent of all marine invertebrate species and 70 percent of terrestrial vertebrate genera disappeared.At the start of the Mesozoic, the remaining biota began a prolonged recovery of diversity and total population numbers, and ecosystems began to resemble those of modern days.Our editors will review what you’ve submitted and determine whether to revise the article.Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work!Earth’s climate during the Mesozoic Era was generally warm, and there was less difference in temperature between equatorial and polar latitudes than there is today.