Dinosaurs
For 165 million years, dinosaurs dominated life on Earth. Humans have been around for 300,000 years. We have existed for less than 0.2% of the time dinosaurs ruled this planet.
Not what you think
Dinosaurs were not the slow, cold-blooded, dim-witted lizards of old films. Modern science shows many were warm-blooded, fast, and possibly feathered. Some were highly social, raised their young, and may have been as intelligent as modern birds. The Jurassic Park image — scaly, sluggish reptiles — is decades out of date.
Thousands of species
Dinosaurs weren't one kind of animal — they were thousands of species across 165 million years. Some were smaller than a chicken. Some, like Argentinosaurus, may have been 30 metres long and weighed 80 tonnes. They filled every ecological niche: predators, herbivores, omnivores, gliders, swimmers, burrowers. The diversity was extraordinary.
Birds are dinosaurs
This is not a metaphor. Birds are the direct descendants of a group of theropod dinosaurs — the same group that included Velociraptor and Tyrannosaurus. When the asteroid struck 66 million years ago, most dinosaur lineages went extinct. One group of feathered, flying theropods survived. Every bird alive today — every sparrow, eagle, chicken, and penguin — is a living dinosaur.
Why they dominated
Dinosaurs first appeared about 230 million years ago following an earlier mass extinction event (the Permian-Triassic extinction, which killed 96% of all species). They were not better than the creatures they replaced — they were lucky survivors who expanded into empty ecological space. Their 165-million-year reign ended not because something better came along, but because a rock from space changed the rules.
The feather-to-flight transition in dinosaurs is one of the best-documented evolutionary sequences in palaeontology. Feathers almost certainly evolved first for insulation and display, not flight. Fossils like Archaeopteryx and the extraordinary feathered dinosaurs from Liaoning Province in China show a gradual continuum between non-flying feathered dinosaurs and early birds. Flight was a later adaptation of features that already existed.