Scientists Uncover Secrets of 66-Million-Year-Old Dinosaur ‘Mummies’

In a groundbreaking study published in the journal Science, researchers have revealed that what were believed to be remarkably preserved dinosaur “mummies” are actually clay casts of their skin. This discovery comes from the Lance Formation in eastern Wyoming, an area known for its rich fossil deposits. The findings have significant implications for understanding the preservation process of dinosaurs from the Late Cretaceous Period.

The research team, led by Dr. Paul Sereno from the University of Chicago, investigated two specimens of the duck-billed dinosaur, Edmontosaurus annectens, found in 2000 and 2001. The specimens displayed exceptional preservation, with features like scales, hooves, and a fleshy crest along the neck. These characteristics prompted the team to explore how such details survived for over 66 million years.

Unraveling the Mystery of Dinosaur Mummies

The initial findings date back to the early 1900s when fossil hunter Charles Sternberg discovered two well-preserved Edmontosaurus skeletons in the same region. At that time, H.F. Osborn, a paleontologist with the American Museum of Natural History, noted that the specimens showed impressions of skin rather than actual preserved tissue. This observation left the nature of the preservation a mystery for over a century.

Using advanced imaging techniques including CT scanning, 3D imaging, and electron microscopy, Sereno’s team analyzed the specimens and found a thin layer of clay, measuring less than one-hundredth of an inch thick, covering the skin. This layer formed as a result of environmental conditions following the dinosaurs’ deaths.

According to Sereno, the original mummies likely died during a prolonged drought, which would have dried their carcasses in the sun. Subsequently, a flash flood buried the remains, leading to the clay coating that preserved the details of their skin. “Clay minerals attract to biological surfaces, ensuring a molding that can reproduce the outermost layers of a body, like skin,” explained Dr. Anthony Martin from Emory University, who did not participate in the study.

A New Perspective on Dinosaur Appearance

The study’s findings provide a detailed portrait of what Edmontosaurus likely looked like. The dinosaur, which could grow over 12 meters (40 feet) long, had a distinctive fleshy crest along its neck and back, with spikes running down its tail. The clay mask revealed previously unknown details, such as the presence of hooves, marking it as the oldest known land animal with this trait.

Sereno humorously noted, “Sorry, mammals, you didn’t invent it,” emphasizing the significance of this discovery. This new understanding not only enhances the knowledge of dinosaur anatomy but also opens avenues for future paleontological explorations, targeting areas with similar sedimentary conditions that could yield more well-preserved specimens.

As interest in these ancient creatures continues to grow, researchers like Dr. Stephanie Drumheller-Horton from the University of Tennessee, Knoxville, highlight the importance of understanding the fossilization process. “If we can understand how and why these fossils form, we can better target where to look to potentially find more of them,” she stated.

The implications of this research extend beyond the realm of paleontology. By revealing the processes that led to the preservation of these remarkable specimens, scientists can better appreciate the complexities of ancient ecosystems and the creatures that inhabited them, enriching our understanding of Earth’s distant past.