Dinosaurs are reptiles that lived in what is known as the Mesozoic era, and their bones can be seen in almost every natural history museum in the world. And for good reason: they were discovered in the 18th century and have since dominated the natural world with their interesting history and their massive size.
But how did they grow so big? And why have there been no other species that could match their size? Click through the following gallery to find all those answers and more.