Researchers have uncovered the most ancient and well-preserved fossils of Pachycephalosaur, a category of dinosaurs distinguished by their domed skulls in Mongolia. A new study was released in the journal Nature on Wednesday.
The fossils, estimated to be between 108 and 105 million years old, belong to a juvenile of an unidentified species, referred to by scientists as Zavasepharelinpoche.
This discovery took place in the Klen Duk Formation in Mongolia’s Gobi Desert, located between China and Russia, and was led by paleontologist Tsogtbaatar Chinzorig from the Mongolian Academy of Sciences.
There is limited knowledge about these two-legged herbivores from the Cretaceous period, particularly in North America, but they are considered one of the “most enigmatic” dinosaur groups, according to the study. Their unique bone structures and representations in media like Jurassic Park have made them quite popular.
Previous finds of Pachycephalosaur fossils were largely restricted to skulls.
“You could fit all Pachycephalosaurus [fossils] known worldwide into two bathtubs, more or less. There are very few fossil examples,” remarked Michael Pittman, a paleontologist at China University in Hong Kong, in an interview with NBC News.
Alessandro Chiarenza / Via Reuters
The Mongolian discoveries are considered “most skeletally complete,” providing greater insight into the anatomy of Pachycephalosaurus than previously available.
The individuals identified as Zavasephale were at least two years old and measured approximately three feet in length. More than half of its skeleton has been recovered, featuring long legs, short arms, small hands, and gastroliths, or stones ingested to aid in digesting vegetation.
Though these animals were not fully grown, their skeletons showed already thickened bones above the skull.
The integrity of the fossils “will be a key specimen for understanding how the cranial dome of Pachycephalosaurus evolved,” said Chinzorig, based on insights from the National Museum of History in London.
Scientists have proposed that Pachycephalosaurus may have engaged in head-butting behavior or used their domes to attract mates, though the precise function of the dome is still undetermined.
These fossils are approximately 15 million years older than previously found Pachycephalosaurus specimens, enhancing our understanding of dinosaur evolution.
“This is the oldest variety we’ve encountered, thus providing insight into what earlier species looked like and how they evolved over time,” stated Pittman. “The discovery of earlier specimens indicates that they have possessed this dome for quite a while.”
Zavasephale was smaller than later species of Pachycephalosaurs, growing to an estimated length of about 14 feet.
Source: www.nbcnews.com
