In the earliest paintings of dinosaurs, from the mid-1800s, they writhe like beached sea serpents or slouch like reptilian potbellied pigs. Now we know better. Dinosaurs stood erect and walked or ran great distances. Many were huge. One species—Argentinosaurus—reached 125 feet long. Now we know dinosaurs had complicated social lives—they raised their young, and they probably lived and hunted together in herds. We even know that the 9,000 species of birds all around us are living, feathered dinosaurs.
We know better because paleontologists are unearthing astounding numbers of fossils. “There are six or seven new species described every year,” says paleontologist Paul Sereno at the University of Chicago. “Even though you’d think it might be slowing down, the pace of discovery has quickened.” Modern technological devices, like CT scanners that illuminate hidden recesses of skulls and molecular probes that detect ancient proteins, offer a new depth of understanding scientists could ...
