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 …

The earliest definitive dinosaur is not one animal but an entire ecosystem containing a few different species. There's no universally accepted dinosaur species that lived earlier in time.

Nov 11, 2025 · Dinosaur - Evolution, Classification, Extinction: After dinosaurs were recognized as a new type of fossil animal, popular fascination with them reached a peak in the 1850s with …

Feb 3, 2025 · With their competitors gone, dinosaurs began to spread and diversify, eventually becoming the dominant land animals for the next 135 million years. The modeling study …

In this post, we’ll take a closer look at the timeline of dinosaurs, from the Triassic period to the Cretaceous period. We’ll explore the unique characteristics of each period, the different types …

Apr 18, 2018 · Like all living creatures, dinosaurs evolved from preexisting ancestors. Here's an overview of what we currently know about dinosaur evolution.

Oct 7, 2025 · The Middle to Late Jurassic period (174-145 million years ago) witnessed the evolution of truly massive dinosaurs, particularly within the sauropod lineage. As Pangaea …

Scientists estimate over a thousand dinosaur species once roamed Earth. Learn which ones were the largest and the smallest, what dinosaurs ate and how they behaved, as well as surprising …

Dinosaurs are a type of reptile, and they evolved from another group of reptiles called ‘dinosauromorphs’ around 250 million years ago. The dinosauromorphs were small 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 …