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Resolving the long-standing enigmas of Deinocheirus for a half century
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  • Date2014/10/23 00:00
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Resolving the long-standing enigmas of 

"Deinocheirus" for a half century

1


- A paper by Dr. Yuong-Nam Lee at KIGAM gets published in the international academic journal Nature

- A long-cherished desire of 50 years of dinosaur academia the world over gets resolved at the lead of a Korean paleontologist


□  In 1965, the fossils of two enormous forelimbs amounting to 2.4m were discovered in the Gobi Desert in Mongolia. This dinosaur fossil that had been named Deinocheirus (formal name: Deinocheirus mirificus, which means “unique and fearsome hands” in Greek), of which a new specimen had not been discovered for 50 years until now, remained the greatest puzzle in dinosaur academia.

□  For the last 50 years, various kinds of conjectures relating to the Deinocheirus have been rampant. One scholar conjectured that because of its forelimbs that were of an enormous size, it would be a carnivorous dinosaur bigger and more ferocious than the Tyrannosaurus. In dinosaur academia without saying, and among dinosaur maniacs on the internet, imaginings of the Deinocheirus in various forms circulated.

□  A research team led by Yuong-Nam Lee (54), head of the KIGAM Geological Museum, clearly revealed what kind of dinosaur the Deinocheirus actually was and is now receiving the whole world’s attention. With the title of ‘‘Resolving the long-standing enigmas of a giant ornithomimosaur Deinocheirus mirificus,’ the outcome of this study has been published in Nature, the international journal that specializes in science. Including Yuong-Nam Lee, head of the Geological Museum (first author) and Hang-Jae Lee, Researcher from KIGAM, R. Barsbold, former head of the Paleontological Center, and T. Chinzorig, Researcher, from the Paleontological Center in Mongolia, Professor P. Currie from the University of Alberta in Canada, Professor Y. Kobayashi from Hokkaido University in Japan, Dr. P. Godefroit from the Royal Belgian Institute of Natural Sciences in Belgium and Dr. F. Escuillie from France participated in the paper.

□  Through the ‘Korea-Mongolia International Dinosaur Expedition (2006-2011)’ project supported by Hwaseong city, in 2006 and 2009, Dr. Lee’s research team excavated two new individual specimens of the Deinocheirus in the Altan Uul and Bugin Tsav regions of the southern Gobi Desert in Mongolia. However, of the Bugin Tsav specimen, the skull and feet bones were of a state where they had already been poached. While this was happening, it was confirmed that an individual in Europe already owned the Deinocheirus bones that had been poached. The research team persuaded the owner to return these bones to Mongolia in the form of a donation, and on May 1st, 2014, the skull and feet bones of this Deinocheirus were returned to Mongolia. At last, nearly all information regarding the Deinocheirus’ skeleton was secured and the research team was able to reveal the true identity of the Deinocheirus.


□ The true identity of Deinocheirus - nearly everything from its form to its diet - that has been revealed through the study has gone wide of conjectures and predictions so far. The general image that people imagined or expected of the Deinocheirus was the biggest carnivorous dinosaur on earth that had enormous forelimbs and that was bigger than the Tyrannosaurus. However, Dr. Lee’s research team revealed that (1) with a full length (from its head to the end of its tail) of approximately 11 meters and a body weight of approximately 6.4 tons, the Deinocheirus was of a similar size to the Tyrannosaurus; (2) its head, back and toes had a very unique shape; (3) it belonged to the Ornithomimosauria group and; (4) it was an omnivorous dinosaur. 


(1) The research team realized a complete reconstruction of the Deinocheirus, based on the fossils of two individual Deinocheirus torsos that were excavated in the Gobi Desert in Mongolia, an arm skeleton that was discovered in 1965 and the skull and feet skeleton that were returned. As a result of the reconstruction, it was revealed that the Deinocheirus’ enormous arms were the distinguishing features of ornithomimosaurs and that it was scientifically unreasonable to make a comparison with the Tyrannosaurus with its short forelimbs that belonged to another group, and that the actual size of the skull indicated that it had the size expected of an ornithomimosaur when fully grown.


(2) ▲ The biggest formal characteristics of the Deinocheirus as seen through the reconstruction are its long forelimbs that had been a symbol of this dinosaur for a long time and the head with a developed beak on top of a long mouth area that was wide and flat like that of a duck. ▲ The neural spine in the back and waist soaring high to the extent that it can be compared to that of a Spinosaurus and bringing to mind a dromedary similarly play a part in the odd image of this dinosaur. ▲ The ends of its claws are not pointed but rather blunt and wide and flat. This is a shape of which no case has been observed in any theropod (carnivorous dinosaur) in the past. Such a characteristic is interpreted as having aided the Deinocheirus so that its feet did not fall deep into wet substrates by the water’s edge.

(3) In addition, the research team revealed that Deinocheirus belongs to the Ornithomimosauria group, ending the long held controversy regarding which group this dinosaur will belong to. ▲ However, the Deinocheirus also shows characteristics that are totally different from those of the typical ornithomimosaur. Like the general characteristics of an ornithomimosaur, it has no teeth and has an exterior form that is similar to that of a bird, but it evolved in a totally different direction from that of typical ornithomimosaurs that were swift and fast, and grew to an enormous size. Posteroventrally tilted hips, robust hind legs, a long femur and big feet state that the Deinocheirus was a slow-walking dinosaur.

(4) The Deinocheirus’ characteristic long forelimbs and front claws that looked like sickles that had caused controversy are interpreted as structures intended for digging and collecting herbaceous plants (plants that had tender stalks) that grew low by the water’s edge. In addition, the remains of fish that were discovered inside the stomach during excavations, more than 1,400 gastroliths and the distinguishing features of the skull that show that it was a herbivorous state that the Deinocheirus was an enormous omnivorous dinosaur.


□  The present study outcome is expected to become one of the hottest issues in paleontological academia this year. Nature has selected and introduced the paper by Dr. Lee’s research team as this week’s paper to receive attention.

□  In particular, the fact that a Korean paleontologist took the lead and completely resolved the mystery of the Deinocheirus, a long-cherished desire for the past 50 years of dinosaur academia the world over and one of the symbolic fossils that represents Mongolia, the most famous place in the world for dinosaur fossils, is a very encouraging thing. This is the very first time that a paleontological study led and researched by a Korean has been published in the journal Nature.

□  In addition, the case of the fossils of the skull and feet bones that had been poached and then donated for the purpose of this present study received praise from paleontological academia for the fact that it showed how important fossils that have been poached or are being illegally traded should be dealt with for the purpose of the development of science.

 Dr. Lee revealed the sentiment, “It is a great honor as a paleontologist to have resolved a big problem in dinosaur academia.” Subsequently, he said, “It would be good if this present achievement became a small occasion whereby paleontology in Korea which is in a slump can see an uptick.”

 Kyu-Han Kim, head of KIGAM said, “We will provide back up with the creation of a creative research environment so that scientists like Dr. Lee can shed more light in the future,” and further stated, “KIGAM will not spare support so that it can take the lead in paleontological research and furthermore, in researching basic sciences in the earth science field.”