Feb 20, 2026 · Dinosaur, the common name given to a group of reptiles, often very large, that first appeared roughly 245 million years ago and thrived worldwide for nearly 180 million years.

Jan 28, 2026 · Dinosaur - Extinction, Fossils, Evolution: Dinosaurs lived in many kinds of terrestrial environments, and although some remains, such as footprints, indicate where dinosaurs actually …

Feb 6, 2026 · 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 the first …

Feb 20, 2026 · Dinosaur - Extinction Causes, Evidence, & Theory: The mass extinction of dinosaurs 66 million years ago remains a misconception; the fossil record shows that dinosaurs were already in …

Feb 20, 2026 · Dinosaur - Reptiles, Extinction, Fossils: The chief difference between the two major groups of dinosaurs is in the configuration of the pelvis. The two dinosaurian orders were named …

This initial period of dinosaur evolution set the stage for their dominance in the Mesozoic Era. Throughout the Mesozoic Era, which lasted from about 252.2 million to 66 million years ago, …

dinosaur, Any of the extinct reptiles that were the dominant land animals during most of the Mesozoic Era (251–65.5 million years ago).

The name dinosaur comes from the Greek words deinos (“terrible” or “fearfully great”) and sauros (“reptile” or “lizard”). Scientists have discovered and named some 1,000 dinosaur species. New …

In contrast, the clade Dinosauromorpha includes all these dinosaurs plus some other dinosaur-like reptiles that possess some, but not all, of the features of dinosaurs.

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