Science, Tech, Math › Animals & Nature 10 Facts About Gigantoraptor Share Flipboard Email Print Animals & Nature Dinosaurs Herbivores Basics Paleontologists Carnivores Dinosaurs & Birds Marine Reptiles Prehistoric Mammals Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated January 15, 2020 The evocatively named Gigantoraptor wasn't really a raptor--but it was still one of the most impressive dinosaurs of the Mesozoic Era. Here are 10 fascinating Gigantoraptor facts. 01 of 10 Gigantoraptor Wasn't Technically a Raptor Wikimedia Commons The Greek root "raptor" (for "thief") is used very loosely, even by paleontologists who should know better. While some dinosaurs with "raptor" in their names (Velociraptor, Buitreraptor, etc.) were true raptors; others, like Gigantoraptor, weren't. Technically, Gigantoraptor is classified as an oviraptorosaur, a bipedal theropod dinosaur closely related to the central Asian Oviraptor. 02 of 10 Gigantoraptor May Have Weighed as Much as Two Tons Sameer Prehistorica Unlike the "-raptor" part, the "giganto" in Gigantoraptor is completely apropos: this dinosaur weighed as much as two tons, putting it in the same weight class as some smaller tyrannosaurs. Gigantoraptor is by far the largest oviraptorosaur yet identified, an order of magnitude bigger than the next-biggest member of the breed, the 500-pound Citipati. 03 of 10 Gigantoraptor Has Been Reconstructed from a Single Fossil Specimen Government of China The only identified species of Gigantoraptor, G. erlianensis, has been reconstructed from a single, near-complete fossil specimen discovered in 2005 in Mongolia. While filming a documentary about the discovery of a new genus of sauropod, Sonidosaurus, a Chinese paleontologist accidentally excavated a Gigantoraptor thighbone, which generated a fair amount of confusion as researchers tried to figure out exactly what type of dinosaur the femur belonged to! 04 of 10 Gigantoraptor Was a Close Relative of Oviraptor Gigantoraptor is classified as an oviraptorosaur, meaning it belonged to that populous central Asian family of two-legged, turkey-like dinosaurs related to Oviraptor. Although these dinosaurs were named for their presumed habit of stealing and eating other dinosaur's eggs, there's no evidence that Oviraptor or its numerous relatives engaged in this activity-, but they did actively brood their young, like most modern birds. 05 of 10 Gigantoraptor May (or May Not) Have Been Covered with Feathers Nobu Tamura Paleontologists believe that oviraptorosaurs were covered partly, or completely, with feathers, which raises some issues with the enormous Gigantoraptor. The feathers of of smaller dinosaurs (and birds) help them to conserve heat, but Gigantoraptor was so big that a full coat of insulating feathers would have cooked it from the inside out! However, there's no reason Gigantoraptor couldn't have been equipped with ornamental feathers, perhaps on its tail or neck. Pending further fossil discoveries, we may never know for sure. 06 of 10 "Baby Louie" May Be a Gigantoraptor Embryo Wikimedia Commons The Childrens' Museum of Indianapolis harbors a very special fossil specimen: an actual dinosaur egg, discovered in central Asia, containing an actual dinosaur embryo. Paleontologists are fairly sure that this egg was laid by an oviraptorosaur, and there's some speculation, given the size of the embryo, that this oviraptorosaur was Gigantoraptor. Since dinosaur eggs are so phenomenally rare, though, there may not be enough evidence to decide this issue either way. 07 of 10 The Claws of Gigantoraptor Were Long and Sharp Wikimedia Commons One of the things that made Gigantoraptor so terrifying (besides its size, of course) was its claws; the long, sharp, lethal weapons that dangled from the ends of its gangly arms. Somewhat incongruously, though, Gigantoraptor seems to have lacked teeth, meaning it almost certainly didn't actively hunt large prey in the manner of its distant North American relative, Tyrannosaurus Rex. So what exactly did Gigantoraptor eat? Let's see in the next slide! 08 of 10 Gigantoraptor's Diet Remains a Mystery Wikimedia Commons As a general rule, the theropod dinosaurs of the Mesozoic Era were devoted meat-eaters, but there are some nagging exceptions. The anatomical evidence points to Gigantoraptor and its oviraptorosaur cousins being near-exclusive herbivores, which may (or may not) have supplemented their vegetarian diets with small animals that they swallowed whole. Given this theory, Gigantoraptor probably wielded its claws to reap low-hanging fruit from trees, or perhaps to intimidate its hungry theropod cousins. 09 of 10 Gigantoraptor Lived During the Late Cretaceous Period Julio Lacerda The type fossil of Gigantoraptor dates to the late Cretaceous period, about 70 million years ago, give or take a few million years, only about five million years before the dinosaurs were rendered extinct by the K/T meteor impact. At this time, central Asia was a lush, teeming ecosystem populated by a huge number of small (and not-so-small) theropod dinosaurs as well as easily hunted prey like the pig-sized Protoceratops. 10 of 10 Gigantoraptor Was Similar in Appearance to Therizinosaurs and Ornithomimids If you've seen one giant, ostrich-shaped dinosaur, you've seen them all--which raises serious problems when it comes to classifying these long-legged beasts. The fact is that Gigantoraptor was very similar in appearance, and probably in behavior, to other strange theropods like therizinosaurs (typified by the tall, gangly Therizinosaurus) and ornithomimids, or "bird mimic" dinosaurs. To show just how narrow these distinctions can be, it took decades for paleontologists to classify another giant theropod, Deinocheirus, as an ornithomimid.