Dinosaur world

The world has not always looked the way it does today. Continents are constantly moving, and this very gradually changes the appearance of the Earth. The Triassic, Jurassic, and Cretaceous worlds all looked very different from one another. Mountains grew up; erosion wore land away, and plants and animals, including the dinosaurs, appeared and disappeared.

Changing Earth

Two plates The Earth's lithosphere (outer layer) is made up of colliding forms massive plates, which move on the semimolten rock underneath. Over millions of years plate movement has ranges caused continents to join together and separate to produce the distribution of land today.

ranges

The layer of semimolten rock beneath the lithosphere is called the mantle.

\ Molten mantle rock surfaces to form new crust.

Moving plates

As the plates move, they either collide, which sometimes forms mountain ranges, or they move apart, forming new crust. When plates move apart, molten mantle rock rises between them, cools, and adds to the Earth's crust.

The layer of semimolten rock beneath the lithosphere is called the mantle.

\ Molten mantle rock surfaces to form new crust.

Edge of plate

The constant movement of the plates is called continental drift.

Edge of plate

World map of plates

Plate bounderies There are nine main plates and several smaller ones. The plates are in constant motion, moving at a rate of only a few inches each year.

Land was joined together triassic world In the Triassic period, when dinosaurs first appeared on Earth, all the land was joined together forming one gigantic continent. Scientists call this supercontinent Pangaea.

Land was joined together

Tethys Sea

Tethys Sea

Laurasia was node up of northern landmasses.,

Sometimes when two plates meet, one slides beneath the other.

jurassic world In the Jurassic period, Pangaea gradually split into two continents. The continent in the north, made of large landmasses and smaller islands, is called Laurasia. The continent in the south is called Gondwanaland.

Gondwanaland

Sometimes when two plates meet, one slides beneath the other.

This landmass became South America.

Gondwanaland

Cretaceous Period World Map

cretaceous world Toward the end of the Cretaceous period, the continents broke up into smaller landmasses. Plates collided, forming the Rocky Mountains in North America and other mountain ranges.

Laurasia was node up of northern landmasses.,

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