[["Dinosaurs first appeared between 247 and 240 million years ago. The first nearly-complete dinosaur skeleton was discovered in 1858. In 1868, that skeleton, Hadrosaurus foulkii, became the first dinosaur skeleton to ever be mounted. ", 838.0], ["The prehistoric reptiles known as dinosaurs arose during the Middle to Late Triassic Period of the Mesozoic Era, some 230 million years ago.", 44.0]]
when was the first dinosaur made
history,dinosaurs