The Mesozoic Era: Facts, Events & Timeline

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: The Paleozoic Era: Definition, Timeline & Events

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:01 The Mesozoic Era
  • 1:37 Continents and Climate
  • 2:47 End of the Mesozoic Era
  • 3:31 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed Audio mode

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Jeff Fennell

Jeff has a master's in engineering and has taught Earth science both domestically and internationally.

The Mesozoic Era began 252 million years ago with the largest mass extinction in Earth's history and ended 66 million years ago with the asteroid that killed off the dinosaurs. This lesson will cover the important events that occurred during the Mesozoic Era.

The Mesozoic Era

The Mesozoic Era is commonly subdivided into three geologic periods:

Triassic (252 to 201.3 million years ago)
Jurassic (201.3 to 145 million years ago)
Cretaceous (145 to 66 million years ago)

The Mesozoic Era begins in the wake of the largest extinction in Earth's history. This extinction took place 252 million years ago and resulted in 96% of marine life and 70% of terrestrial life dying out. The cause of the extinction is not fully understood, but eventually it led to dinosaurs dominating the planet for 135 million years.

The rise of the dinosaurs began at the end of the Triassic Period. This gave rise to a two-legged omnivore roughly three feet long named Eoraptor. Scientists believe the Eoraptor thrived and evolved into the many species of dinosaurs that would dominate the planet during the Jurassic period.

Dinosaurs dominated the planet for 135 million years during the Jurassic and Cretaceous Periods. The age of the dinosaurs saw over 1,000 different species covering land and the ocean. One of the largest dinosaurs discovered to date was the Argentinosaurus, weighing as much as 200,000 pounds.

Continents and Climate of the Mesozoic Era

The Mesozoic Era began with today's continents combined into one large land mass known as Pangea, which was surrounded by a single global ocean called Panthalassa.

During the Jurassic Period, a rift between modern day Africa and South America began to split Pangea apart. This began the formation of the continents as we know them today. Even today, this same rift continues to spread the coasts of the Atlantic further apart.

It is believed that the Mesozoic Era was a dry climate for most of the time due to the abundance of evaporates, which is a type of mineral that only forms in dry climates. Fossils from the Mesozoic also indicate a warm and dry climate.

One such example is the finding of fern fossils in high latitudes (areas that are generally cold now) from this era that appear to have existed in a warm climate. Ferns today cannot survive freezing temperatures, which leaves two possibilities: either the high altitudes were generally warmer for the ferns to survive, or ferns from the Mesozoic were able to withstand cold temperatures.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account