Exceptionally Preserved Dinosaur Fossils Reveal Hooves and Skin Details

Paleontologists from the University of Chicago have unveiled two exceptionally preserved Edmontosaurus fossils from Wyoming, offering unprecedented insights into the anatomy of these duck-billed dinosaurs. The specimens, dating back 66 million years to the late Cretaceous period, were found encased in thin clay layers that preserved detailed features such as skin, spikes, and notably, hooves—the first documented in any reptile.

The fossils include a young adult approximately 40 feet long and a juvenile about half that size. The preservation process, termed "clay templating," involved a thin clay film forming over the decaying carcasses, capturing the external morphology in remarkable detail. This discovery challenges previous assumptions about dinosaur integument and suggests that Edmontosaurus possessed a more complex hide than previously thought.

The presence of hooves indicates that Edmontosaurus may have been well-adapted for traversing hard terrain, drawing parallels to modern hoofed mammals. Additionally, the fossils reveal a fleshy crest along the neck and trunk, transitioning into a row of spikes down the tail, and skin covered in small, pebble-like scales. These findings provide the most complete view of a large dinosaur's external anatomy to date.

The study, led by paleontologist Paul Sereno, was published in the journal Science. Sereno noted, "We're seeing the full profile of the dinosaur for the first time." The research not only enhances understanding of Edmontosaurus but also offers new perspectives on dinosaur preservation and the environments that facilitated such exceptional fossilization.