Two extremely rare dinosaur “mummies” discovered in a Wyoming wasteland are the first examples of ungulate reptiles, according to a new study.
Although the fossil is not a real mummy, as the original tissue has been replaced with rock, it provided scientists with an unprecedented look into the biology of duck-billed dinosaurs and confirmed that they did have hooves. The researchers reported their findings in the journal Science on October 23.
you may like
“This is the first time we have truly confidently obtained a complete, fleshed-out view of a large dinosaur,” study lead author Paul Sereno, a professor of biological biology and anatomy at the University of Chicago, said in a statement.
Duck-billed dinosaurs used their hooves to trample through mud at the end of the Cretaceous period (145 million to 66 million years ago). They lived alongside other large dinosaurs such as Tyrannosaurus rex and Triceratops just before a giant asteroid crashed into Earth, collapsing the age of dinosaurs and making all dinosaurs extinct except for birds.
Dinosaur mummies are extremely well-preserved fossils that contain clay copies of dinosaur skin and other organic tissue. Some of these fossils were discovered in Wyoming in the early 1900s and inspired new research. Sereno and his colleagues discovered the two new specimens by tracing the location of historical discoveries using old photographs and letters, and by mapping what they call the “mummy zone.”
One of the newly discovered Edmontosaurus specimens, named Ed Jr., was a late juvenile, estimated to be about 2 years old at the time of death. The other individual, nicknamed “Ed Senior,” was an early adult, between 5 and 8 years old at the time of his death.
The researchers used a variety of imaging techniques, including X-rays and micro-CT scans, as well as analyzing clay, surveying the discovery site, and studying fossilized duck-billed dinosaur footprints to reconstruct the dinosaur’s ecology, movements, and preservation status.
The dinosaur had a fleshy crest along its neck and body, which turned into a row of spikes at its tail. The animal’s lower body and tail are also dotted with small pebble-like scales, the largest of which are just 4 millimeters (0.2 inches) in diameter, extremely small considering the dinosaur could grow to more than 40 feet (12 meters) long, the statement said.
The researchers determined that the dinosaur’s body was dried in the sun, resulting in a mummified preservation, so it may have died from drought before being quickly covered by flash floods. Static electricity reacting with microorganisms on the carcass’s surface sucked up clay from the wet sediment, which later formed a thin template around the carcass. The organic material then slowly decayed and was replaced by rock.
“These duck-beak mummies preserve a number of amazing ‘firsts’: the oldest hoof ever recorded in a land vertebrate, the first ungulate reptile, and the first ungulate quadruped with different front and hind limb postures,” Sereno said.
Source link
