“High-Crested Tooth” discovered in the 19th Century the Morrison Formation, described & named in 1977 by Peter Galton after its discoverer Prof. Othniel Charles Marsh. Othnielia lived during the Late Jurassic Period about 156 to 145 million years ago. It was 1.1 meters (4 feet) in length, .6 meters (2 feet) in height, & 22 pounds (10 kilograms) in weight.