The years spanning 2000 to 2010 yielded some important dinosaur discoveries, as well as a few surprises from the world of pterosaurs, mammals and prehistoric crocodiles. Here's a list of the top 10 fossil discoveries of the last decade.
At the turn of the century, paleontologists working at the famous Liaoning fossil beds in northeastern China discovered a strange creature: a tiny (only three or four pounds) raptor with thick tufts of feathers along its front and back legs, giving it the appearance of having four wings. Was Microraptor an intermediate stage between dinosaurs and birds, or an evolutionary experiment that went nowhere? Ten years later, scientists still aren't sure.
Otherwise an unremarkable hadrosaur, or duck-billed dinosaur, Brachylophosaurus dominated the decade thanks to the discovery of three near-complete, virtually mummified specimens, some of which bore the evidence of fossilized internal organs. Since then, researchers have scanned and probed the remains with ever-more-advanced technology, puzzling out the rarely preserved internal anatomy that made herbivorous dinosaurs click.
Technically, Sarcosuchus was discovered in the late 1990's, but this prehistoric crocodile has loomed large in the popular imagination ever since. "SuperCroc," as it's sometimes called, measured a whopping 40 feet long and 8 tons, and had a strange bulb on the end of its snout. Its impact on paleontology can be felt even today; for example, three brand-new prehistoric crocodiles have been dubbed BoarCroc, RatCroc and PancakeCroc.
As so often happens in paleontology, the fossils of Fruitadens were discovered in the Fruita region of Colorado in the late 1970's, but were only "diagnosed" and named in 2009. What makes this Heterodontosaurus-like dinosaur important is its tiny size: Adult Fruitadens weighed only a pound or so, putting them in direct competition with the tiny mammals that scurried beneath the feet of gigantic sauropods during the late Jurassic period.
Alongside behemoths like Sarcosuchus and Gigantoraptor, the 00's were dominated by smaller dinosaurs (witness Microraptor and Fruitadens, above). One of the more recent finds is Raptorex, which its amazed discoverers describe as a "fully scaled-down T. Rex" that lived more than 50 million years before its more famous counterpart. Work is still being done, but the relatively "evolved" anatomy of Raptorex may prompt some revisions in the tyrannosaur family tree.
We all know that dinosaurs ate mammals; how about a mammal that ate dinosaurs? During the early Cretaceous period, most mammals were the size of mice, but the Asian Repenonamus grew to a relatively gargantuan 25 pounds--and occasionally chowed down on reptiles, as evidenced by the remains of a Psittacosaurus discovered (in 2005) in the stomach of a Repenomamus specimen. Other early mammals may have snacked on dinosaurs, but to date, Repenonamus represents the only proof.
Another relatively recent inclusion on this list, Darwinopterus is believed to have been the long-sought "transitional form" between two kinds of pterosaurs: the small, early, big-headed and long-tailed rhamphorhynchoids, and the bigger, more recent, sleeker-headed and shorter-tailed pterodactyloids. A good indication of Darwinopterus' importance to paleontologists is its name: not every ancient reptile is named after the founding father of evolutionary theory!
In 2005, paleontologists unearthed a treasure trove in Utah, the remains of hundreds of previously unknown, medium-sized dinosaurs with long necks and long, clawed hands. Analysis of these bones showed something extraordinary: the middle Cretaceous Falcarius was a Therizinosaurus-like theropod that had evolved toward a vegetarian lifestyle, a marked departure from its more famous (and better understood) raptor and tyrannosaur cousins.
Oviraptor has long been one of the most-misunderstood dinosaurs, unfairly accused of stealing other dinosaur's eggs. Well, it turns out that Oviraptor could have called on its huge, two-ton cousin Gigantoraptor to defend its reputation. Discovered in central Asia in 2005, Gigantoraptor is the biggest oviraptor-like dinosaur yet known, and it likely sported a Big Bird-like coat of feathers. (And no, despite its name, Gigantoraptor wasn't a true raptor like Velociraptor.)
Sometimes, dinosaurs are important for what they aren't, rather than what they are. A few years ago, the Childrens' Museum of Indianapolis invited visitors to name a new genus of pachycephalosaur, the winning entry being Dracorex Hogwartsia ("Dragon King of Hogwarts"). Now, new research has shown that Dracorex may not merit its own genus, having been a juvenile of an existing species of Pachycephalosaurus. No matter the decade, it seems, kids just can't win!