Era · Before c. 3000 BC
From the formation of Earth and the age of dinosaurs to the first cave art and monuments, before writing was invented.
The two men named well over a hundred new species of dinosaurs between them, including Stegosaurus, Triceratops and Diplodocus, but the feud damaged both their reputations and finances.
At least 38 Iguanodon skeletons were recovered and taken to Brussels, giving the first complete picture of a dinosaur's skeleton and correcting earlier reconstructions.
The skeleton was named Diplodocus carnegii, and Carnegie's plaster casts made it the most widely displayed dinosaur in the world.
Brown's partial skeleton became the type specimen of Tyrannosaurus rex, named by Osborn in 1905, and later finds made it the world's most famous dinosaur.
Douglass's quarry yielded thousands of Jurassic dinosaur bones, and the site became Dinosaur National Monument in 1915, famed for its exposed wall of bones.
Some 225 tonnes or more of fossil material reached Berlin, including the giant sauropod Giraffatitan, mounted in 1937 and still one of the tallest dinosaur skeletons on display.
Stromer named Spinosaurus aegyptiacus in 1915, but the original fossils were destroyed in an Allied air raid on Munich in April 1944, leaving only drawings, notes and photographs.
The Central Asiatic Expeditions found the first fossil eggs widely recognised as dinosaur eggs, along with new Late Cretaceous dinosaurs and mammals.
The quarry yielded hundreds of skeletons of the early dinosaur Coelophysis, making it one of the best-known Triassic dinosaurs.
Deinonychus showed that some dinosaurs were agile, active predators and revived the theory that birds descend from dinosaurs.
The expedition recovered a unique fossil of a predator and its prey buried in mid-fight, now regarded as a Mongolian national treasure.
The discovery of Maiasaura nests with juveniles provided the first strong evidence that some dinosaurs nested in colonies and cared for their young.
