Diplodocus was a genus of DINOSAUR that lived during the late Jurassic period. It was one of the longest and heaviest animals to ever walk the Earth, measuring up to 27 meters long and weighing up to 12 tonnes. Diplodocus had a long neck and tail, and its four legs were built for walking on land. Its diet consisted mainly of plants, and it had peg-like teeth for chewing them. Diplodocus is one of the most iconic dinosaurs, and its fossils have been found in North America and Europe.