Wyoming dinosaur 'mummies' reveal a surprise: Hoofed feet

Two fossilized “mummies” unearthed by scientists in the badlands of Wyoming of the duckbilled dinosaur Edmontosaurus reveal the external anatomy in exquisite detail, including the surprising presence of hooves on the feet — a first for any dinosaur

Two fossilized “mummies” unearthed by scientists in the badlands of Wyoming of the duckbilled dinosaur Edmontosaurus reveal the external anatomy in exquisite detail, including the surprising presence of hooves on the feet — a first for any dinosaur.

The two Edmontosaurus individuals, dating to the very end of the dinosaur age 66 million years ago, were a young adult roughly 40 feet (12.2 meters) long and a two-year-old juvenile about half that length. The contours of the external fleshy surface of the two dinosaurs were preserved over the skeleton by a thin clay layer about one-hundredth of an inch (0.025 cm) thick that formed after they died.

Because the shape of an animal’s soft tissue is rarely preserved in fossils, it is usually difficult to reconstruct the appearance of dinosaurs and other extinct creatures. But these two had extensive continuous areas of preserved external skin surface, providing the most complete, fleshed-out view of a large dinosaur to date.

The fossilized “mummy” of the duck-billed dinosaur Edmontosaurus at the Fossil Lab in Chicago, Ill.Tyler Keillor/Fossil Lab / via Reuters“We’re seeing the full profile of the dinosaur for the first time,” said University of Chicago paleontologist Paul Sereno, who led the study published in the journal Science. “We’re confident what it looked like.”

The dinosaurs are not mummies in the same sense as bodies elaborately preserved in ancient Egypt for the afterlife. But similar fossils were found more than a century ago in the same locale — though not excavated as painstakingly as these — that were dubbed mummies, and the term stuck.