Paleontologists have discovered a new genus and species of ankylosaur that roamed what is now the Gobi Desert in Mongolia during the Upper Cretaceous, between 100.5 and 66 million years ago.
Life restoration of Zaraapelta nomadis. Image credit: Danielle Dufault.
The new dinosaur is named Zaraapelta nomadis. It belongs to Ankylosauridae, a family of herbivorous dinosaurs with armored plates on their back.
The genus name Zaraapelta is a combination of the Mongolian and Greek works for ‘hedgehog’ and ‘shield’ in reference to its spiky appearance.
The species name nomadis honors the Mongolian company Nomadic Expeditions, which has facilitated paleontological fieldwork in the Gobi Desert for almost two decades.
Zaraapelta nomadis’ skull that is missing the front of the snout was uncovered from the Upper Cretaceous Baruungoyot Formation of Mongolia in 2000.
Like some of the other ankylosaurs from the Gobi Desert, the top of its skull was bumpy and spiky. At the back of its skull there are distinctive horns with a prominent ridge along the top.
Now, the skull is part of the collections of the Mongolian Paleontological Center in Ulaanbaatar.
“The elaborate and distinctive ornamentation on the skulls of Zaraapelta nomadis and other Mongolian ankylosaurs may have evolved as a way to show off to members of the opposite sex,” said Dr Victoria Arbour of the University of Alberta, who is the lead author of a study published in the Zoological Journal of the Linnean Society.
A partial skull of Zaraapelta nomadis. Image credit: Victoria M. Arbour et al.
“It has long been thought that other kinds of dinosaurs, like the crested hadrosaurs or ceratopsians with their horns and frills, used these ornaments during sexual displays, but the idea hasn’t been applied to ankylosaurs.”
In addition to naming the new ankylosaur Zaraapelta nomadis, this study also re-examined previously named ankylosaurs from Mongolia and found support for resurrecting a species that had been discarded by earlier studies.
“Sometimes, researchers might determine that two species names represent only one actual species, in which case the name that was created first has priority. This was the case for an ankylosaur called Tarchia kielanae, which was eventually thought to be the same kind of ankylosaur as Tarchia gigantean,” Dr Arbour said.
“But new information from recent dinosaur discoveries, including this study, suggests that Tarchia kielanae might be a separate species after all, so the name has been brought back into use.”
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Victoria M. Arbour et al. 2014. The ankylosaurid dinosaurs of the Upper Cretaceous Baruungoyot and Nemegt formations of Mongolia. Zoological Journal of the Linnean Society, vol. 172, no. 3, pp. 631–652; doi: 10.1111/zoj.12185
