‘Teen’ fossil sheds gentle on mysterious dinosaurs

A “teenaged” pachycephalosaur from Mongolia’s Gobi Desert might present solutions to lingering questions across the dinosaur group, based on new analysis.

The fossil represents a brand new species of pachycephalosaur and is each the oldest and most full skeleton of this dinosaur group discovered so far.

“This specimen is a once-in-a-lifetime discovery.”

“Pachycephalosaurs are iconic dinosaurs, but they’re also rare and mysterious,” says Lindsay Zanno, affiliate analysis professor at North Carolina State University, head of paleontology on the North Carolina Museum of Natural Sciences, and corresponding creator of the work.

The specimen was found within the Khuren Dukh locality of the Eastern Gobi Basin by Tsogtbaatar Chinzorig from the Mongolian Academy of Sciences, who’s the lead creator of the paper and at present a analysis assistant at NC State.

The new species is named Zavacephale rinpoche, which is the mix of zava, which means “root” or “origin” in Tibetan, and cephal, which means “head” in Latin. The particular identify, “rinpoche,” or “precious one” in Tibetan, refers back to the domed cranium found uncovered on a cliff like a cabochon jewel.

Z. rinpoche lived round 108 million years in the past throughout the Early Cretaceous interval in what’s now Mongolia’s Gobi Desert. At the time, the world was a valley dotted with lakes and surrounded by cliffs or escarpments. Pachycephalosaurs have been plant eaters, and adults might develop to round 14 toes lengthy (4.3 meters) and 7 toes tall (2.1 meters), weighing 800–900 kilos (363–410 kilograms).

“Z. rinpoche predates all known pachycephalosaur fossils to date by about 15 million years,” Chinzorig says. “It was a small animal—about three feet or less than one meter long—and the most skeletally complete specimen yet found.”

The Z. rinpoche specimen the workforce found was not absolutely grown when it died. However, it already sported a totally shaped dome, although with out a lot of the extra ornamentation discovered on different pachycephalosaur fossils.

“Z. rinpoche is an important specimen for understanding the cranial dome development of pachycephalosaurs, which has been debated for a long time due to the absence of early diverging or pre-Late Cretaceous species and the fragmentary nature of nearly all pachycephalosaurian fossils,” Chinzorig says.

How to inform whether or not two skulls that look totally different belong to 2 distinct species or simply totally different progress phases of the identical species is a long-standing debate for paleontologists who examine this group, and that’s the place Z. rinpoche is available in.

“Pachycephalosaurs are all about the bling, but we can’t use flashy signaling structures alone to figure out what species they belong to or what growth stage they’re in because some cranial ornamentation changes as animals mature,” Zanno says.

“We age dinosaurs by looking at growth rings in bones, but most pachycephalosaur skeletons are just isolated, fragmentary skulls,” Zanno provides. “Z. rinpoche is a spectacular find because it has limbs and a complete skull, allowing us to couple growth stage and dome development for the first time.”

By inspecting a skinny slice of the specimen’s decrease leg bone, the researchers decided that, regardless of sporting a totally shaped dome, this Z. rinpoche was nonetheless a juvenile when it died.

Pachycephalosaurs are well-known for his or her massive domed skulls and are sometimes depicted utilizing these domes to duel in epic headbutting contests.

“The consensus is that these dinosaurs used the dome for socio-sexual behaviors,” Zanno says. “The domes wouldn’t have helped towards predators or for temperature regulation, in order that they have been most definitely for displaying off and competing for mates.

“If you need to headbutt yourself into a relationship, it’s a good idea to start rehearsing early,” she says.

Z. rinpoche fills in large gaps within the pachycephalosaur timeline—each by way of once they lived and the way they grew, the researchers say.

“This specimen is a once-in-a-lifetime discovery. It is remarkable for being the oldest definitive pachycephalosaur, pushing back the fossil record of this group by at least 15 million years, but also because of how complete and well-preserved it is,” Zanno says.

“Z. rinpoche gives us an unprecedented glimpse into the anatomy and biology of pachycephalosaurs, including what their hands looked like and that they used stomach stones to grind food.”

“The newly recovered materials of Z. rinpoche, such as the hand elements, the stomach stones (gastroliths), and an articulated tail with covered tendons, reshape our understanding of the paleobiology, locomotion, and body plan of these ‘mysterious’ dinosaurs,” Chinzorig says.

The work seems in Nature.

Support for the work got here from the National Geographic Society.

Additional researchers from the Okayama University of Science, the Fukushima Museum, the Institute of Paleontology of the Mongolian Academy of Sciences, and Stellenbosch University contributed to the work.

Source: North Carolina State University