Tuesday, October 22, 2019
How Velociraptor Was Discovered
How Velociraptor Was Discovered Of all the dinosaurs that have been discovered over the last 200 years, Velociraptor comes closest to the romantic ideal of rugged paleontologists trekking across dangerous, windswept terrain in search of ancient fossils. Ironically, though, this dinosaur was nowhere near as smart and vicious as it has subsequently been depicted in movies, the main culprit being Jurassic Parks pack-hunting, quick-thinking, doorknob-turning Velociraptors (which were actually played by individuals of the closely related raptor genus Deinonychus, and even then not all that accurately). The Velociraptors of the Gobi Desert In the early 1920s, Mongolia (located in central Asia) was one of the most remote places on the face of the earth, inaccessible by train, plane, or pretty much anything else except a well-stocked caravan of well-oiled automobiles and sturdy horses. That is exactly what New Yorks American Museum of Natural History dispatched to outer Mongolia, by way of western China, in a series of fossil-hunting expeditions led by the famous paleontologist Roy Chapman Andrews. Although Andrews personally discovered and named many Mongolian dinosaurs in the early 1920s- including Oviraptor and Protoceratops- the honor of unearthing Velociraptor went to one of his associates, Peter Kaisen, who stumbled upon a crushed skull and toe claw at a dig site in the Gobi Desert. Unfortunately for Kaisen, the honor of naming Velociraptor didnt go to him, or even to Andrews, but to Henry Fairfield Osborn, the president of the American Museum of Natural History (who, after all, wrote all the checks). Osborn referred to this dinosaur as Ovoraptor in a popular magazine article; fortunately for generations of schoolkids (can you imagine having to distinguish between Ovoraptor and Oviraptor?) he settled on Velociraptor mongoliensis (speedy thief from Mongolia) for his scientific paper. Velociraptor Behind the Iron Curtain It was difficult enough to send an American expedition to the Gobi Desert in the early 1920s; that became a political impossibility only a few years later, as the Mongolian government was toppled by a Communist revolution and the Soviet Union exerted its hegemony over Mongolian science. (The Peoples Republic of China didnt come into existence until 1949, giving the USSR a crucial head start in a Mongolian nation that, today, is dominated by China rather than Russia.) The upshot was that, for over 50 years, the American Museum of Natural History was excluded from any further Velociraptor-hunting expeditions. After World War II, Mongolian scientists, aided by colleagues from the USSR and Poland, returned repeatedly to the Flaming Cliffs fossil site where the original Velociraptor specimens had been unearthed. The most famous discovery- of a near-complete Velociraptor caught in the act of grappling with an equally well-preserved Protoceratops- was announced in 1971. In the late 1980s, following the crumbling of the Soviet Union and its satellites, western scientists were again able to travel in Mongolia. This was when a joint Chinese and Canadian team discovered Velociraptor specimens in northern China, and a joint Mongolian and American team unearthed additional Velociraptors at the Flaming Cliffs site. (One of the specimens discovered on this latter expedition was informally named Ichabodcraniosaurus, after Nathaniel Hawthornes headless horseman because it was missing its skull.) Later, in 2007, paleontologists discovered a Velociraptor forearm bearing the unmistakable imprint of quills- the first definite proof that (as had long been suspected) Velociraptor sported feathers rather than reptilian scales. The Feathered Theropods of Central Asia As famous as it is, Velociraptor was far from the only feathered, meat-eating dinosaur of late Cretaceous central Asia. The ground was thick with dino-birds closely related to the North American Troodon, including Saurornithoides, Linhevenator, Byronosaurus, and the wonderfully named Zanabazar; feathered dinosaurs closely related to Oviraptor, including Heyuannia, Citipati, Conchoraptor, and the (also) wonderfully named Khaan; and a vast assortment of associated raptors. Most of these dinosaurs were discovered in the late 20th century, under the auspices of a talented generation of Chinese paleontologists. What was it about the windswept Mongolian plains that favored this brand of dinosaur diversity? Clearly, conditions in late Cretaceous central Asiaà favored small, skittery animals that could nimbly pursue smaller prey or speedily escape from the clutches of slightly bigger dino-birds. In fact, the profusion of central Asian feathered dinosaurs points to the most likely explanation for the evolution of flight: originally evolved for the purposes of insulation and display, feathers gave dinosaurs a certain amount of lift while they were running, and were thus increasingly favored by natural selection until one lucky reptile achieved actual lift-off!
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.