For the first time, paleontologists successfully reconstructed the profiles of two massive platypus dinosaursright down to their rocky skin and unexpected hooves. Based in part on remains discovered decades ago in the Wyoming badlands, the couple Edmontosaurus annextens the specimens were only preserved through an extremely rare and delicate process of “mummification”.
Meet the platypuses
Measuring approximately 39 feet in length and weighing approximately 6.2 tons, E. annectens was one of the largest and most widespread dinosaurs in what is now North America during the Late Cretaceous period. It was also literally one of the last of its kind. Fossil records dating back to 68–66 million years ago indicate E. annectens probably existed before Cretaceous-Paleogene extinction this eventually killed all non-avian dinosaurs.
Edmontosaurus They were probably quite remarkable for their long, low skull and one of the most prominent duck-billed snouts of any hadrosaurs. Although paleontologists had previously discovered various skeletal fragments and more than 20 skulls, partially or completely, they were not entirely sure of its overall anatomy.
How a dinosaur becomes a “mummy”
To better understand the creature, a University of Chicago team led by anatomist Paul Sereno tracked the historical sites of previous dinosaur finds in east-central Wyoming. In particular, they identified a small area known for its “mummies”, including two new E. annectens the specimens discovered by Sereno's team are late juveniles and early adults.
“The Wyoming Badlands where the finds were made constitute a unique 'mummy zone,'” Sereno. says the statement.
This is not mummies in the traditional sense of the word. There are no organic remains, but the dinosaurs' anatomy, such as skin, hooves and spines, is preserved in a submillimeter film of clay during a process called clay template making. Making one of these mummies requires what Sereno calls a “random preservation event,” which occurs shortly after the dinosaur's death and burial.
“It’s a mask, a template, a layer of clay so thin you can blow it off,” he explained.
Sereno's team used several imaging techniques, such as micro-CT and X-ray spectroscopy, to carefully analyze how this process might occur. They believe the most likely scenario begins when a flash flood covers the sun-dried dinosaur carcass. As waters wash over the body, the biofilm on the animal's skin electrostatically pulls clay from the surrounding sediment, forming a thin “template layer.” This layer then preserved the surface underneath in three dimensions as the dinosaur's organic matter continued to decompose before its skeleton eventually fossilized.
While the dinosaur pattern is often unprecedented in its detail, it is also extremely precise: experts from the UChicago Fossil Laboratory spent hours clearing the clay boundary. Other team members continued to conduct surface and CT scans of the skeleton and study the fossilized traces. The final results are described in a study published Oct. 23 in the journal Science offer never-before-seen looks at the dinosaur pair.
“The two specimens complemented each other perfectly. For the first time, we could see the entire profile rather than isolated areas,” Sereno said.
Single spines, polygonal scales and hooves.
Paleontologists were able to identify a continuous median anatomical feature on E. annectens It started as a ridge along the neck and torso and then developed into a single row of spines on the hips and down the tail. Each spine grew directly above and corresponded to one corresponding vertebra. The dinosaur's lower body and tail skin had larger, polygonal scales, although most were the size of small pebbles. Dinosaurs are usually the size of E. annectens differed on a larger scale. Wrinkles remaining on the chest also indicate thin skin.
However, the most unexpected discovery occurred on the hind legs of the larger mummy. Each of them had three toes, covered with a wedge-shaped hoof with a flat bottom, similar to a horse. Combined with additional studies of fossilized duckbill tracks from the same era, the team reconstructed the overall appearance. Now it seems that E. annectens walked with the front paws touching the ground only with their hooves, and the hind paws also had a fleshy heel pad for support.
“There are so many amazing ‘new things’ preserved in these duck-billed mummies,” Sereno said. “The earliest hooves recorded in a terrestrial vertebrate, the first confirmed ungulate reptile, and the first ungulate quadruped with different forelimb and hindlimb positions.”
The study authors hope that other researchers will now be able to apply the methods described in their study to other dinosaur mummies. In the meantime, they plan to conduct searches throughout Wyoming to find similar examples for their work.
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