New Discoveries of Edmontosaurus Mummies Transform Dinosaur Understanding

Researchers have made groundbreaking discoveries in Wyoming, uncovering new mummies of the dinosaur species Edmontosaurus annectens. This large, herbivorous dinosaur, which existed toward the end of the Cretaceous period, has been a subject of fascination since its initial discovery in 1908 by fossil collector C.H. Sternberg. The newly found mummies are providing unprecedented insights into the dinosaur’s external anatomy.

Unraveling the Past

The original skeleton of Edmontosaurus, later known as the “AMNH mummy,” was housed at the American Museum of Natural History in New York. It was the first fossil to provide clues about the dinosaur’s appearance, showcasing scaly skin imprinted in the surrounding sediment. More than a century later, a team of paleontologists led by Paul C. Sereno, a professor at the University of Chicago, returned to the same area in east-central Wyoming where Sternberg unearthed the original specimen. Their exploration resulted in the discovery of two additional Edmontosaurus mummies, each preserving intricate details of the dinosaur’s flesh.

These new findings allow researchers to accurately visualize Edmontosaurus, revealing details such as the size of its scales and the arrangement of spikes on its tail. Sereno noted that this research has significantly changed the perception of Edmontosaurus, which has evolved over time through various artistic interpretations.

A History of Interpretation

The first illustration of Edmontosaurus was created in 1909 by renowned paleoartist Charles R. Knight. His depiction was based on incomplete information, including a specimen lacking a tail. As a result, Knight’s artistic vision led to a portrayal resembling a dragon. Subsequent updates, particularly one by influential paleontologist Jack Horner in 1984, attempted to correct earlier mistakes, yet still presented inaccuracies.

Sereno’s team retraced Sternberg’s steps to locate the “mummy zone,” an area teeming with Cretaceous fossils. This endeavor relied on historical notes and interviews with local farmers, ultimately leading them to a site less than 10 kilometers in diameter known for its rich geological history.

The fossils were found in the Lance Formation, a geological layer formed during the last three million years of the Cretaceous period. This formation extends through several states, including North Dakota, South Dakota, Wyoming, and Montana, and even reaches parts of Canada. Sereno explained that sedimentation rates in this region were exceptionally high, likely due to frequent flooding from a nearby river.

Clay Templating and Detailed Imaging

The research team’s discoveries hinge on a process known as clay templating, where sediment adheres to the skin of decaying organisms, preserving fine details. This technique, traditionally associated with deep-sea invertebrates, has now provided a remarkable glimpse into the appearance of large dinosaurs like Edmontosaurus.

Using modern imaging technologies such as CT scans and photogrammetry, the team created a detailed model of the dinosaur’s skin. This model revealed significant updates, including changes to the crest, spikes, and an unexpected finding: the presence of hooves. Both Knight’s and Horner’s interpretations were partially correct, but Sereno’s team discovered that the fleshy crest transitioned into a row of spikes along the spine.

Additionally, the analysis showed that Edmontosaurus had small scales, measuring just 1 to 4 millimeters across, resembling those of modern lizards. The thinness of the skin was evident from the imaging, and the presence of hooves indicated evolutionary traits previously undocumented in dinosaurs.

These findings position Edmontosaurus as a significant species in the study of dinosaur evolution, showcasing characteristics that challenge previous notions about dinosaur physiology.

Future Discoveries

While the research primarily focused on Edmontosaurus, Sereno’s team has also discovered mummies of other dinosaurs in the same region. Notably, they unearthed a T. rex mummy preserved in a lifelike pose, suggesting it may have been buried alive, and a Triceratops mummy, which exhibits striking differences in scale size and skin texture compared to Edmontosaurus.

Sereno is particularly excited about the Triceratops findings, noting that the scales were significantly larger and the skin structure differed drastically, indicating varied physiology despite the dinosaurs cohabiting the same environment. He emphasized that these discoveries represent merely the beginning of a new era in paleontological research.

As the scientific community anticipates further studies and publications from Sereno’s team, the revelations about Edmontosaurus and its contemporaries are poised to reshape our understanding of these ancient creatures and their environments.

Overall, this research not only highlights the remarkable advancements in paleontological techniques but also underscores the ongoing quest to unlock the secrets of the past, revealing the intricate details of life during the age of dinosaurs.

For more detailed insights and findings, refer to the upcoming papers from Sereno’s team, set to be published in 2025 in the journal Science.