Friday, November 28, 2014

Thanks for Deinocheirus

This Thanksgiving I’m thankful for everything, but there’s one thing in particular that I’m thankful for that is related to paleontology.   As everyone tucks into their theropod for dinner,  I’m going to talk about a theropod that not only am I very thankful for, but would require enough stuffing to fill a Volkswagen. The mystery has been solved and the truth has turned out to be stranger than fiction. Today I’m talking about Deinocheirus

Our story begins in 1965. The Soviet Union can’t keep its natural scientists down, and so Polish teams and scientists assemble in Warsaw University and head off to Mongolia.  The Soviets have been going there for the past 20 years ever since seizing influence in Mongolia from Japan. Professor Zofia Kielan-Jaworowska leads the expedition.  Other women in the team, Teresa Maryańska and the late great Halszka Osmólska would go on to lead their own expeditions.  Two years before, they found Gallimimus, a big ornithomimid. This time they found giant, mysterious bones.
The rest of the skeleton was buried deep in the rock, but they excavated a few vertebra, gastralia, ribs, and most importantly a huge pair of claws. These are the biggest arms ever found with a theropod dinosaur, each larger than any of the paleontologists. Recently they were sent to Ulaan Bator’s Mongolian Natural History Museum.  Replicas were sent to Oslo, New York, and London, and today can be found all over the world. I even saw one cast in Kenosha. 5 years later, the aforementioned student Osmólska described it as a giant basal ornithomimid, the same size as Tyrannosaurus, that hunted small animals and scavenged large ones. This didn’t stop other paleontologists to think of other ideas; even Jaworowska thought it was a titanic megalosaur superpredator. Some envisioned a huge carnosaurian predator with a giant maw full of teeth. Others imagined a titanic dromaeosaur.  David Lambert speculated it as a predator that eviscerated sauropods with its claws. Russian paleontologist Anatoly Rozhdestvensky was so confused he speculated that it was a slothlike animal that climbed up gigantic trees. Gregory Paul also thought of sloths, albeit giant ground sloths of his native North America, using their great claws to hook branches and long ornithomimid neck to probe the canopy like a giraffe.

For years, all we had were those giant arms. They travelled Europe, and casts have been seen on every continent. It would be a mystery for 40 years.

In 2006 and 2009, weird fossils appeared on the fossil market, discovered from Mongolia. Rumors spread about these mysterious finds. They had been poached from their native stone, and wound up being sold in Japan. The Japanese dealers in turn sold them to Germany,  and then in turn to the Royal Belgian Institute of Natural Sciences. For three years, they were stuck in storage, the museum not having enough funds to investigate and unwilling to exhibit such dubious fossils.  Finally, they wound up back in Mongolia, and a huge team of paleontologists got to work on them.  Yuong-Nam Lee (top Korean scientist), Rinchen Barsbold (legendary Mongolian  paleontologist who led the Eastern Block in evolutionary science), Philip J. Currie (Canadian theropod master and curator of the Royal Tyrell Museum), Yoshitsugu Kobayashi (from Hokkaido University and Japan’s leading dinosaur paleontologist), Hang-Jae Lee (a more obscure figure, probably one of Yuong Nam Lee’s students), Pascal Godefroit (accompanying the fossil from Brussels), François Escuillié (the paleontologist and fossil dealer that purchased the find for Godefroiot) & Tsogtbaatar Chinzorig (one of Barsbold’s successors  and students) wrote this year a paper describing the find. 

The specimens comprised two individuals, one gigantic the other smaller. Each had bones missing from the other, so together they created a composite picture of this strange giant. The truth was more bizarre than imagined. Sadly, Osmolska had passed before seeing this discovery, but her guess was right-it was the biggest ornithomimosaur ever.   It proved even stranger-the back supported a 6-foot sail or hump like that of a spinosaur. The last two bones of the tail were fused, possibly a pygostyle, a structure that supports tail feathers. Deinochierus probably did have feathers-a specimen of Ornithomimus was preserved with them, as were many other coelurosaurs.  Finally, the skull has been recovered after being poached and sold in the market.  Said skull is about 4 feet long and similar to its neighbor Gallimimus with a toothless beak. The main difference is that the tip is flared like that of a hadrosaur or duckbill dinosaur. All these features combine to make a bizarre animal Gastroliths were found inside its gut, giving it an impressive gizzard. As I said in a previous blog post, it’s very likely these kinds of animals were omnivores, eating plants, carrion, fish, and smaller animals. 

Deinocheirus lived in the Nemegt Formation of Mongolia, about 70 million years ago, the last Asian dinosaur fauna, a warm and wet biome near the east coast of Asia.  Oviraptorids made up the small omnivores-Ajancingenia, Conchoraptor, Elmisaurus, Nemegtomaia, Nomingia, Rinchenia, Avimimus (all from incomplete remains and could be synonyms of each other).  The flying bird Gurilynia, the waterfowl Teviornis and the penguinlike Judinornis  were already specialized birds, and took niches that would continue to be held by birds even now.  Troodonts, small intelligent theropods, were successful as well with the three species Tochisaurus, Zanabazar, Borogovia probably taking different ecological roles.  As in North America at the same time, the dromaeosaurs have declined to only one genus, in this case Adasaurus.  Deinocherius was the largest ornithomimid, but shared the area with its relatives Gallimimus and Anserimimus.  Two Tyrannosaurus made up the large predators-Alioramus (equivalent to the American Nanotyrannus) and Tarbosaurus (equivalent to Tyrannosaurus itself). The largest herbivores were the titanosaurs Nemegtosaurus and Opisthocoelicaudia, which may be synonymous.  Hadrosaurs were big, too, with both the Asian Saurolophus species and Barsboldia being quite impressive. It’s very likely the Chinese hadrosaur Shantungosaurus, the largest ornithopod ever, may have lived there too.  Small herbivores were the Pachycephalosaurs Homalocephale and Prenocephale. Other herbivores consisted of the ankylosaurs Tarchia and Saichania, the gigantic Therizinosaurus (the third largest theropod following closely behind Tarbosaurus and Deinocheirus), and the strange little Alvarezosaur Mononykus.  No pterosaurs are known from here, but there is a mammal, Buginbaatar, belonging to the multitubercate group of mammals that flourished in the Paleocene before being wiped out by the Eocene extinction.

As you can probably guess, there’s very little on it in the media. You can’t make a movie on a pair of arms. Fortunately, there’s some new art on it-Luis Rey has made a rendition based on the new fossils.  So hopefully we can look forward to Deinocheirus books, films, documentaries, toys and art in the future. It’s not  as popular as Spinosaurus, sadly, but it’s just as bizarre and almost as big.
So anyway, Hollywood, give this guy a break. Museums, put him on display. Toy companies, here’s a new fresh face. Authors, think about the crap you’re writing and how this genus could perk up the place. And remember, shop Deinocheirus where you work or play.

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