International Research Team Identifies New Armored Dinosaur Species Found in Mongolia's Gobi Desert
DALLAS (SMU) – A new species of armored dinosaur from the southern Gobi Desert of Mongolia that may have used its unique tail as a weapon has been identified by an international team of vertebrate paleontologists and researchers.
Researchers from SMU (Southern Methodist University in Dallas, Texas) and universities in South Korea, Japan, and Mongolia identified the new species of ankylosaurid dinosaur and named it Tarchia tumanovae sp. nov.
Its bones were collected from the Upper Cretaceous Nemegt Formation in 2008 during the Korea-Mongolia International Dinosaur Expedition and included a well-preserved skull, vertebrae, sixteen dorsal ribs, pelvic bones, free osteoderms (bony deposits forming plates), and a tail club. The discovery and the team’s findings were recently published in the Scientific Reports journal of Nature Publishing Group.
The research team includes two graduates from SMU’s doctoral program in geology, Yuong-Nam Lee, professor of vertebrate paleontology at Seoul National University, and Yoshitsugu Kobayashi, professor of vertebrate paleontology at Hokkaido University Museum, Japan. Joinging Lee as co-lead of the team was Rinchen Barsbold, a paleonologist and geologist with the Mongolian Academy of Sciences.
Louis L. Jacobs, professor emeritus of earth sciences and president of ISEM, an interdisciplinary institute at SMU, and Michael J. Polcyn, research associate and director of the Digital Earth Sciences Laboratory at SMU, were also on the team. Jacobs supervised Lee and Kobayashi when they were students in the doctoral program at SMU.
Researchers identified the dinosaur’s armor, beak, and tail as having unique characteristics.
“Ankylosaurid dinosaurs are quadrupedal, herbivorous, and have a heavily ornamented skull and parallel rows of osteoderms, or plates, covering the back and sides of the body,” Lee said. He described the new ankylosaur as having a poorly healed ossified tendon on its tail knob handle – “a possible injury due to active tail use during combat, suggesting agonistic behavior.”
The dinosaur also has “an anteriorly protruded shovel-shaped beak, which is a morphological character of selective feeders. Ankylosaurid diets in Mongolia shifted from low-level bulk feeding to selective feeding during the Late Cretaceous based on the shape of the beak. This ankylosaurid niche shifting might have responded to habitat change and competition with other bulk-feeding herbivores like the duck-billed dinosaur, Saurolophus,” Lee added.
Lee’s first discovery of a new dinosaur species occurred while he was in the doctoral program under Jacobs supervision at SMU.
“A new nodosaurid (one of two types of armored dinosaurs), Pawpawsaurus campbelli, was found in Fort Worth and described by myself in 1996 when I was a Ph.D. student at SMU,” Lee said. “Since then, I have been interested in armored dinosaurs.”
Lee directed the Korea-Mongolia International Dinosaur Expedition (KID) between 2006 and 2010. He invited Jacobs, Polcyn, and other SMU doctoral students to the expedition. The new ankylosaur, Lee says, was recovered mainly by the SMU team in 2008 at Hermiin Tsav in the southern Gobi Desert of Mongolia.
“This kind of discovery is particularly rewarding when it results from working with our former students and Mongolian colleagues and friends,” Jacobs said. “We are very proud of our former Ph.D. students’ role in leading this effort and for their contributions to our profession. Being with them at the site when this dinosaur was recovered was pretty special.”
“Discovering a new dinosaur species is always exhilarating,” Polcyn said. “But, being able to participate on the dig team with SMU colleagues and former students that unearthed the species makes it more memorable,” he added.
Lee believes the discovery is important as it helps better explain how dinosaurs evolved over time. Dinosaurs first evolved during the early stage of the Mesozoic Era, known as the Triassic period. That stage was followed by the Jurassic and then the Cretaceous periods.
“The Mesozoic Era is the most important geologic time in terms of vertebrate animal evolution. Almost all main groups evolved during the Triassic Period. They are mammals, turtles, marine reptiles, lizards, including snakes, pterosaurs, crocodiles, and dinosaurs, including birds,” Lee said. “So, their evolution patterns are fascinating and complex. This new ankylosaur added one piece of evidence to understand the evolutionary dynamics of dinosaurs in the world,” he said.
“Animals traveled between Asia and North America during the Cretaceous Period,” Lee said. “Dinosaurs are one of them, so we need to understand the geological and evolutionary history of these regions based on fossil records. Therefore, the discovery of any new dinosaur is valuable,” he said.
“New discoveries always push us to go to the field to find another fascinating fossil in the Gobi. I have been going to the Gobi Desert to hunt dinosaurs every year since 2006,” Lee added.
Lee designed the project and was supported by a grant from Hwaseong City, Gyeonggi Province, South Korea. The research was supported by grants from the National Research Foundation of Korea.
Other members of the research team include Jin-Young Park, a professor at Seoul National University; Hang-Jae Lee and Kyo-Young Song, professors at the Korea Institute of Geoscience and Mineral Resources; and Namsoo Kim, a professor at Yonsei University.
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