More than a century after Charles H. Sternberg’s famed “mummy” Edmontosaurus finds in Wyoming, a team led by Paul Sereno of the University of Chicago has uncovered two more in the same six-mile-wide “mummy zone.” Described in Science, the fossils preserve rare details, including the first known dinosaur hooves, and suggest a new pathway to mummification: carcasses dried out, were buried by floods, and microbes entombed their hides in a thin clay-like biofilm. CT scans detected no remaining organic compounds. An outside expert called the specimens “ridiculously beautiful” and said the work could guide searches for additional Mesozoic mummies.

Prepared by Olivia Bennett and reviewed by editorial team.