Dinosaurs inhabited the earth during the Mesozoic Era, which spanned from 252 to 66 million years ago. Commonly known as the “Age of Dinosaurs,” this era is divided into three specific periods: the Triassic, the Jurassic, and the Cretaceous. The extinction of dinosaurs is believed to have occurred when an asteroid collided with Earth, releasing minerals into the atmosphere that triggered a prolonged winter and inhibited plant growth. As a result of the food shortage, many species faced extinction.
Humans have been uncovering dinosaurs since 1822, when British paleontologist Mary Ann Mantell made the first discovery of fossilized bones. This timeline may continue to evolve as paleontologists are discovering new fossils at an astonishing rate. According to the Smithsonian, a new dinosaur species is identified every two weeks from various locations around the globe. These findings have resulted in significant changes to the dinosaur family tree.
Paleontologists’ understanding of dinosaurs, including their size and types, changes over time as new fossils are discovered. In the 200 years since the first fossil discovery, there have been 11,000 fossils unearthed. Each year the Smithsonian publishes a list of the top dinosaur finds. The current record holder for the largest dinosaur is the Argentinosaurus found in Argentina in 2012.
There is debate over whether “largest” should be based on weight or length. The Argentinosaurus measures 131 feet long and weighs 110 tons, making it the largest by both metrics. (Today, this is the biggest animal in the world.)
