Dec 22, 2025 · Dinosaurs are a diverse group of reptiles that were the dominant terrestrial life form on Earth during the Mesozoic Era, about 245 million years ago. Dinosaurs went into decline near the …

Dinosaurs are a diverse group of reptiles [note 1] of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and …

Oct 27, 2009 · Scientists first began studying dinosaurs during the 1820s, when they discovered the bones of a large land reptile they dubbed a Megalosaurus (“big lizard”) buried in the English …

Learn about dinosaurs at the Museum: facts, photos, games for kids, lesson plans for educators, and more.

Dinosaurs dominated Earth during the Mesozoic Era. But what was the first dinosaur, what did they look like and where did they come from?

Dec 5, 2024 · The group of animals that we today call dinosaurs was first recognized scientifically during the 1840s. At this time, British anatomist Richard Owen proposed that three large fossil reptiles, all...

Aug 25, 2025 · Included are books that focus on the history of the field of paleontology and the study of dinosaurs. The following materials include links to fuller bibliographic information in the Library of …

The history of dinosaurs spans millions of years. Learn about the different periods of the dinosaur timeline, from the Triassic to the Cretaceous, and explore the fascinating world of these prehistoric …

The dinosaur timeline chart is a complete map of evolution itself. It spans the three major geological periods that include the Triassic, Jurassic, and Cretaceous periods.

Jul 31, 2025 · The age of dinosaurs—also known as the Mesozoic Era—is divided into three periods: the Triassic, the Jurassic, and the Cretaceous. This stretch of time, from about 252 to 66 million years …