For hundreds of millions of years, dinosaurs roamed the Earth. But 66 million years ago, a large asteroid hit Earth, which wiped out most dinosaurs.

What are dinosaurs?

Dinosaurs are reptiles that existed on Earth until 66 million years ago, when a lot of them were wiped out by an asteroid hitting Earth. There are a few dinosaurs that still exist today.

Types of dinosaurs

There are many types of dinosaurs, from raptors to the T-Rex.

This isn’t a complete list of dinosaurs, but this is a summary of the main types of dinosaurs.

T-Rex/Tyrannosaurus rex

The T-Rex, or the tyrannosaurus rex, is one of the largest dinosaurs known to exist. It is well-known for it’s small arms and large head. They were up to 4 metres tall and they ate both animals and plants. The T-Rex existed around 68 million years ago. Teeth fossils were first discovered by Arthur Lakes in 1874, and further fossils from other T-Rex body parts have been found since then.


Raptors were dinosaurs known for their feathers, long tail and a large claw on each foot. Like most dinosaurs, raptors ate other animals. Nearly all raptor fossils were originally found in Mongolia.

Based on the age of raptor fossils, raptors existed between 70 and 83 million years ago.

A raptor dinosaur | TurboSquid


The stegosaurus existed around 150 million years ago. It is known for the plates of armour that it had on it’s back. The stegosaurus was named by Othniel Charles Marsh in 1877.

Stegosauruses were around 3 metres (around 9ft) tall and ate plants such as ferns and conifer trees.

A 3D model of a stegosaurus | ArtStation


Theropods are dinosaurs that have 3 toes on their feet and hollow bones. The largest theropods are ostriches, which still exist today and are 2.74 metres (9ft) tall.


Sauropods are dinosaurs that had long necks, small heads and pillar-like legs. Some sauropods are known as some of the largest animals to have existed on land.

An illustration of what sauropods looked like | NovaTaxa

The mass-extinction event

66 million years ago, an asteroid collided with Earth, killing off almost all of the dinosaurs. We know that the dinosaurs existed because of the fossils they left behind.

The asteroid hit near where Mexico is today. Any animals within 900 miles of it would probably have been wiped out instantly.

Surviving dinosaurs

There are some dinosaurs that have survived to this very day. One of these is crocodiles, who have been around for 80 million years.