The Cretaceous Period

The Cretaceous Period

Musée du Séminaire de Sherbrooke

© Musée du Séminaire de Sherbrooke. All Rights Reserved.


The Earth formed 4.6 billion years ago and life appeared 800 million years later. To guide them through this long history of life, scientists have created a time scale based on the study of fossils and geological layers. The Cretaceous period extends from 145 to 65.5 million years ago. It’s characterized by chalk deposits. In fact, the Latin word for chalk (creta) gave the period its name.

If the history of life were a 24-hour day, the Cretaceous period would take place between 11 and 11:30 p.m. Human life would appear one and a half minutes before midnight and civilization less than a second before midnight. And you thought your grandparents were old!
The Earth formed 4.6 billion years ago and life appeared 800 million years later. To guide them through this long history of life, scientists have created a time scale based on the study of fossils and geological layers. The Cretaceous period extends from 145 to 65.5 million years ago. It’s characterized by chalk deposits. In fact, the Latin word for chalk (creta) gave the period its name.

If the history of life were a 24-hour day, the Cretaceous period would take place between 11 and 11:30 p.m. Human life would appear one and a half minutes before midnight and civilization less than a second before midnight. And you thought your grandparents were old!

© 2001, CHIN. All Rights Reserved.

Why are some species found on more than one continent separated by large oceans? Well, scientists know the continents were once linked. But the continents drifted apart because of the movement of rigid pieces of the Earth’s crust called tectonic plates.

In the Cretaceous period, the Atlantic Ocean grew larger and larger. The south of North America separated from Europe and joined South America. But the north remained attached to Europe. During this continental drift, the earth’s crust buckled and volcanoes often spewed lava.
Why are some species found on more than one continent separated by large oceans? Well, scientists know the continents were once linked. But the continents drifted apart because of the movement of rigid pieces of the Earth’s crust called tectonic plates.

In the Cretaceous period, the Atlantic Ocean grew larger and larger. The south of North America separated from Europe and joined South America. But the north remained attached to Europe. During this continental drift, the earth’s crust buckled and volcanoes often spewed lava.

© 2001, CHIN. All Rights Reserved.

The continents’ shorelines changed constantly. Tectonic movement formed the first mountain peaks in the western part of North America. A huge inland sea separated these emerging mountains from the Appalachians. As a result, the Arctic Ocean was linked to the Gulf of Mexico through the continent’s interior.

There was much more water available because the polar caps were almost non- existent. Indeed, the forms of animal and plant life alive back then suggest temperatures were warmer and more stable than today.
The continents’ shorelines changed constantly. Tectonic movement formed the first mountain peaks in the western part of North America. A huge inland sea separated these emerging mountains from the Appalachians. As a result, the Arctic Ocean was linked to the Gulf of Mexico through the continent’s interior.

There was much more water available because the polar caps were almost non- existent. Indeed, the forms of animal and plant life alive back then suggest temperatures were warmer and more stable than today.

© 2001, CHIN. All Rights Reserved.

Map of the World in the Cretaceous Period

Map of the World in the Cretaceous Period

CHIN

© Musée du Séminaire de Sherbrooke


Learning Objectives

The learner will:
  • Develop enthusiasm and continuing interest in the study of science
  • Define the Cretaceous period
  • Describe tectonic plates and some basic changes that have occurred on the Earth over deep time

Teachers' Centre Home Page | Find Learning Resources & Lesson Plans