The ferocious, intelligent pack of velociraptors in the Jurassic Park were somewhat controversial at the time of the film’s release. In the early 1990s, scientists had only a few hints that any dinosaurs hunted in packs like wolves do today. But now, the evidence is piling up, and the latest addition is a pile of bones encased in a nine-ton block of sandstone.
Once quicksand, the sandstone block now holds the fossilized bones of at least six Utahraptors, including an adult, four juveniles and a baby. "Covered in feathers, with a huge sickle claw on each second toe, Utahraptor looked like a pumped-up version of the Jurassic Park star Velociraptor," writes Brian Switek for National Geographic. Also in the trove is the remains of a herbivore called an iguanodont. And more fossils, yet to be viewed, lie within the block (which was recently excavated in Utah).
The whole mess suggests that a pack, or even a family, of the raptors succumbed to a quicksand death while pursuing the trapped herbivore. It could be some of the best evidence for social raptors yet discovered.
The pack-hunting dinos in Jurassic Park may have been called velociraptors, but they were much bigger than the Velociraptor fossils we’ve found. Switek argues that they were probably modeled after the larger Deinonychus, another member of the bird-like family of dinosaurs called dromaosauridae. The Utahraptor is the largest known member of that same family.
Analyzing the new find could help determine whether this family of dinosaurs really hunted in packs. Several lines of previously discovered evidence back up the idea. For example, paleontologist John Ostrom found three Deinonychus near a herbivore fossil found in a Montana quarry. Also, "numerous Deinonychus teeth were discovered among the remains of the same prey at fourteen other sites," writes Switek for the Guardian. Still, those findings could be interpreted as scavengers converging on a meal, fighting over the scraps and killing each other in the process.
Instead, footprints of a group of Utahraptor-like predators pursuing prey discovered in China offer more evidence of pack-like behavior. If the excavation of the Utah block of sandstone reveals intertangled limbs, indicating that the dinosaurs met their fate en masse rather than piling up one by one, that could help fill in the story even more.
Then, at least, we’d know that Jurassic Park’s pack-hunting depiction is correct. The next nitpicking fact to tackle is easy enough to decide: The smooth and scaly skin of their dinosaurs (which persists even in the upcoming Jurassic World) is certainly wrong. These dromaeosaurids, including Velociraptors, most certainly had feathers.