Dinosaur | Definition, Types, History, Names, & Facts | Britannica
2024年12月9日 · dinosaur, (clade Dinosauria), the common name given to a group of reptiles, often very large, that first appeared roughly 245 million years ago (near the beginning of the Middle Triassic Epoch) and thrived worldwide for nearly 180 million years.
Dinosaur - Wikipedia
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 timing of the evolution of dinosaurs is a subject of active research.
What are dinosaurs? - Natural History Museum
Dinosaurs are a group of reptiles that dominated the land for over 140 million years (more than 160 million years in some parts of the world). They evolved diverse shapes and sizes, from the fearsome giant Spinosaurus to the chicken-sized Microraptor, and were able to …
What Makes a Dinosaur a Dinosaur - U.S. National Park Service
What makes a dinosaur a dinosaur? There are several ways of answering this question, some more accurate (and useful!) than others. A popular but very inaccurate definition calls any big extinct reptile-like animal a dinosaur. This would include everything from the sail-backed mammal cousin Dimetrodon, to marine reptiles, to flying pterosaurs!
Dinosaur Facts - American Museum of Natural History
Dinosaurs are a group of reptiles that have lived on Earth for about 245 million years. In 1842, the English naturalist Sir Richard Owen coined the term Dinosauria, derived from the Greek deinos, meaning “fearfully great,” and sauros, meaning “lizard.” Dinosaur fossils have been found on all seven continents.
What is a Dinosaur? - Natural History Museum
What is a Dinosaur? Dinosaurs were a specialized group of land reptiles that lived during the Mesozoic Era, also called the "Age of Dinosaurs". The Mesozoic was the period of time between 252 million and 66 million years ago.
Dinosaur - Simple English Wikipedia, the free encyclopedia
Dinosaurs are a group of Archosaur reptiles of the clade Dinosauria. [1] Dinosaurs eventually gave rise to birds. Dinosaurs were the most powerful land animals of the Mesozoic era. Over 500 different genera of dinosaurs are known. [2] Fossils of …
Dinosaurs - American Museum of Natural History
Dinosaurs are a group of reptiles that first appeared about 245 million years ago. They dominated the planet until an extinction event wiped out a large swath of life on Earth about 66 million years ago. But now we know that the Age of Dinosaurs never ended. Instead, a group of dinosaurs gave rise to a new, small airborne form: birds.
What is a Dinosaur? | Blog | Science Museum of Virginia
2021年8月27日 · Dinosaurs are a type of reptile known as archosaurs, a group that includes crocodiles, pterosaurs and birds but excludes snakes and lizards, tuataras, and the extinct marine reptiles such as plesiosaurs and mosasaurs.
Dinosaurs are prehistoric reptiles that have lived on Earth from about 228 million years ago to the present. Modern birds are one kind of dinosaur because they share a common ancestor with non-avian dinosaurs. Non-avian dinosaurs (all dinosaurs besides birds), which are now extinct, varied greatly in shape and size.