The Edmontosaurus was a type of Hadrosaur, or duck-billed dinosaur, which could grow to be 32 feet in length and weigh between 3 to 4 tons (Dr. Sharp, who stands about 6 foot, is shown in this illustration for perspective).  There have been a number of fossilized dinosaur eggs found, and surprisingly they are extremely small (for the size of the animal).  The largest egg belongs to a Sauropod called Hypselosaurus (High Lizard), which could grow to 40 feet in length, but its egg was a ball shaped structure only 10 inches in diameter.  Dr. Jack Horner, of Montana State University, made a discovery of several eggs of a Hadrosaur called Maiasaurus (Mother Lizard) in which the tiny skeleton of the unborn dinosaur had fossilized inside one of the eggs.  The Maiasaurus could grow to be 30 feet in length, but the babies were only 11 to 12 inches long at birth.  The Brachiosaurus, which could grow to be 75 feet long, 40 feet high and weigh 75 tons, had an egg that was the size of a football.