Steggie has greeted Museum visitors since his arrival in 1968. Stegosaurus lived in the late Jurassic, from 156 million to 145 million years ago. An herbivore, its most distinct feature is the arrangement of plates along its back, which vary in size and appearance. It is one of the world's most recognized dinosaurs, both for its striking appearance and its discovery early in the history of dinosaur hunting. The first Steggie, created by New York sculptor Paul Jonas for the 1964-65 World's Fair in New York, was retired when the Museum commissioned an identical copy from the original casts in 1997. Now refurbished, the original resides at the Berkshire Museum in Pittsfield, Massachusetts, where it is called "Wally" in honor of Stegosaurus' walnut-sized brain—estimated to weigh just 2.5 ounces.