They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is a subject of active research.

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 …

Non-bird dinosaurs lived between about 245 and 66 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans, Homo sapiens, appeared. …

Oct 27, 2009 · Dinosaurs mysteriously disappeared at the end of the Cretaceous Period, around 65 million years ago.

This era ended up introducing some of the most famous dinosaurs in the history of the dinosaur timeline. The most prominent examples were the Tyrannosaurus rex, Triceratops, Velociraptor, Ankylosaurus, …

Aug 16, 2025 · The era when dinosaurs flourished is known as the Mesozoic Era, often called the “Age of Dinosaurs.” This vast geological interval began approximately 252 million years ago and …

Jul 21, 2024 · Explore the dinosaurs, marine animals, and other life from 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 …

Dec 3, 2021 · Take a trip back to the Mesozoic Era to explore how geologic events, ecosystems and evolution were connected during the so-called age of dinosaurs.

Jun 24, 2025 · Dinosaurs reigned supreme on Earth for approximately 180 million years, beginning around 252 million years ago and culminating 66 million years ago with the Cretaceous-Paleogene …