In 1993, fossil hunter Mike Hammer excavated the remains of a Thescelosaurus in South Dakota. The dinosaur was named Willo after the wife of the property owner. The North Carolina Museum of Natural Sciences purchased the skeleton in 1996 and brought it to Raleigh. Willo is displayed in its original posture, still embedded in the sandstone in which it rested for millions of years. What makes this dinosaur unique is that the specimen contains a fossilized heart.