The Milwaukee Public Museum provided certification that Dovetail Gallery's dinosaur egg is the only prehistoric egg on display in Wisconsin. The 70 million year old Hypselosaurus egg, along with two CT scans, is a remarkable piece of history.
The Hypselosaurus Priscus (high-ridge lizard) lived in the late Cretaceous era about 70 million years ago. These members of the titanosaurid dinosaur family evolved from Alaska and Russia and spread to Europe. Hypselosaurus was a medium-sized cousin of the brontosaurus with peg-shaped teeth that were too weak for chewing. Hypselosaurus grew to about 40 feet in length and weighed about ten tons.
The eggs of this dinosaur are special in two ways: they were the first dinosaur eggs ever found and they are the largest dinosaur eggs known to date. The volume of the eggs is about half a gallon, and they are twice the size of ostrich eggs. They have been measured at around 1-foot (0.30 m) in length. The Hypselosaurus egg at the Dovetail Gallery was found near the Aude River in the Pyrenees Mountains of France. According to a visiting palentologist, only 1/10th of 1 % of dinosaur eggs have remains inside.
Once owned by Steven Spielberg, director of Jurassic Park, this Hypselosaurus egg has been authenticated as real and rare, complete with an MRI scan revealing the embryo of this docile 40-foot dinosaur. The egg still has a Hypselosaurus baby inside, but it will never hatch because it's been fossilized. Seventy million years ago a landslide or flood probably buried the nest and egg. Water, rock and dirt turned to sediment, which kept the egg safe. Later, the sediment turned to stone, water invaded it, and eventually it eroded and revealed dinosaur nesting sites.