Wyoming Dinosaur 'Mummies' Reveal Unexpected Hoofed Feet

Recent excavations in Wyoming have uncovered two exceptionally well-preserved fossils of the duck-billed dinosaur Edmontosaurus, providing unprecedented insights into the species' anatomy. The specimens, a young adult approximately 40 feet long and a juvenile about half that size, date back 66 million years to the end of the Cretaceous Period. Notably, these fossils reveal the presence of hoof-like structures on the dinosaurs' feet—a first for any known dinosaur species.

The preservation process involved a thin clay layer, approximately 0.025 cm thick, that formed over the skeletons post-mortem. This clay templating preserved extensive details of the external skin surface, offering the most complete view of a large dinosaur to date.

Paul Sereno, a paleontologist at the University of Chicago who led the study, stated, "We're seeing the full profile of the dinosaur for the first time. We're confident what it looked like."

The discovery of hoof-like structures suggests that Edmontosaurus evolved features similar to those of modern mammals such as horses and cows, exemplifying convergent evolution. These hooves likely facilitated efficient movement over hard terrain.

Additionally, the fossils exhibit a continuous midline feature with a fleshy crest along the neck and trunk, transitioning into a single row of spikes down the tail. The skin was covered in small, pebble-like scales, most comparable in size to those of an average lizard.

These findings, published in the journal Science, enhance our understanding of dinosaur biology and behavior, highlighting the importance of soft tissue preservation in paleontological research.