There is no definitive answer as to when the very first dinosaur bones were discovered. I like to think that when the ancient Mongolians and Chinese happened upon what they described as dragon bones over 2000 years ago, what they had in fact found were most likely dinosaur fossils. If early scientists had no idea what they were dealing with when the first fossils were found, you can see how the ancient peoples of Asia developed legends of the fearsome dragon when they stumbled across them. Today dinosaurs are still as much a part of our pop culture as they ever were, simultaneously terrifying and captivating they are forever stuck in our headspace.
In 1948, a Mongolian exploratory expedition uncovered the remains of what is considered to be the most bizarre dinosaur discovered to date, the Therizinosaurus. Thought to have lived around 70 million years ago, the Therizinosaurus is a genus of very large theropod dinosaurs. What was found in the southwest region of Mongolia, was a colossal claw measuring up to a metre in length. The claw itself was so extraordinary it was mistakenly thought to be the single rib bone of a turtle like reptile, which is how the species name T. cheloniformis – ‘turtle-formed’ came about. It would be many years before subsequent fossil finds in Northern China would enable palaeontologists to piece together a general skeletal structure and identify the find as that of a dinosaur.
The dentition of bite characteristics is the best way to determine an animal’s diet. With no skull ever having been found palaeontologists are still bickering over whether this odd-looking beastie was herbivore, omnivore, or carnivore. They are also undecided on the exact purpose of its huge curved claws, debate on the subject still throwing up many a hypothesis. With so little information at hand scientists have had little choice but to draw inferences on the physiognomy of the Therizinosaurus based on data supplied by the study of other therizinosauridae.
Estimations based on skeletal reconstruction have the Therizinosaurus weighing in at a hefty 3 tons and growing to lengths of 30-36ft. Their necks were elongated, and it is thought they had distended pot bellies caused by the fermentation of the tons of roughage they may have eaten. Their metre length arciform claws were attached to forelimbs that were themselves 10ft long, and it’s this feature that sets the Therizinosaurus apart from all other theropods. There are three main theories on just what those ginormous claws were for. Some say they were used in interspecies combat between males, others suggest they were for display, the large claw indicating reproductive maturity. The third option is they were used to reach up into the tree tops and pull down the copious amounts of vegetation it required. To others it’s plain they evolved to inspire Tim Burton’s ‘Edwards Scissorhands’.
Present day scientific consensus has modern day birds evolving from Mesozoic era theropod dinosaurs. Aspects linking birds to theropod dinosaurs are the brooding of eggs ( see coelurosaurs), skeletal pneumaticity (air-filled bones), the presence of furcula (wishbones), and of course feathers. This may be why representations of the Therizinosaurus vary. Mostly illustrated featherless they are sometimes depicted with them. However, to date there is no direct evidence of this dinosaur having had feathers. It’s also worth noting that creatures of such a size had very little need for insulation of any sort on the grounds of gigantothermy. The Therizinosaurus is a dinosaur mystery that remains unsolved, and until a skull or complete skeleton presents itself researchers, palaeontologists and Dino-nerds will be kept guessing.
For more information on conservation projects in Mongolia and Bhutan or to book one of our Birding, Trekking, Botany or Wildlife Tours, please contact 020 3877 0670