In Utah, a dinosaur "death trap" that holds the biggest fossil treasure trove ever found is revealing some secrets about a particular predatory species, suggesting that they hunted in pacts, according to new research.
The remains of at least six Utahraptors - a more massive and ferocious version of Jurassic Park's famous velociraptors - along with those of some herbivores, have been unearthed so far at the site. The graveyard was actually found about a decade ago, but it wasn't until 2013 that scientists first tried to move this marvel, embedded on a steep slope near Moab, Utah, for further study.
While work is still being done to uncover all of the fossils in this nine-ton block of sandstone, it is already changing scientists' views of Utahraptors.
The fact that all these dinosaurs died together suggests that they may have hunted in groups. This would possibly mean that the silver screen got it right, with Jurassic Park showing these predators communicating and cooperating together to chase down prey, as well as resolve a long-standing debate among scientists about their hunting habits.
"We're really going to have a different view of this guy," lead researcher James Kirkland told National Geographic.
"If a careful study of sedimentology supports the idea that this was a predator trap, and the dromaeosaur bones are all found fossilized in a similar condition and a position that indicates that they were mired, then I think the team will have a solid case that this is more than just a jumble of bones, but evidence that some dromaeosaurs did live and hunt together socially," added University of Edinburgh paleontologist Stephen Brusatte, who was not involved in the research.
Utahraptors (Utahraptorostrommaysorum) are one of the oldest and largest known dromaeosaurids, explains the Natural History Museum of Utah, roaming the Earth some 125 million years ago. Like their velociraptor cousins, these carnivores have a large, 9.5-inch retractable claw on their foot, especially sharp for cutting into prey. Even with this terrifying talon, was tracking down their prey a joint effort?
By chipping off smaller pieces of the block, Kirkland and his team have discovered bones from a 16-foot-long adult Utahraptor, four juveniles, and a baby that was probably only three feet long. And alongside these dinos was a beaked, bipedal herbivore called an iguanodont.
Based on their observations, the researchers believe that this prey got stuck in quicksand in the mountainside, attracting several hungry Utahraptors looking for a meal, only for each of them one by one to get stuck in the mud also, ending in a tragic scene.
"Any time you find multiple dinosaurs together it's a big deal," Brusatte said.
Researchers plan to continue studying this fossil treasure trove, which will hopefully reveal some more clues about the behavior of Utahraptors, dating back to the Early Cretaceous period. Kirkland and his team used brute strength and heavy machinery to get the dinosaurs off the hill, for the block was too heavy even for helicopters to carry. For now, the remains will reside in a temporary home at Salt Lake City's Department of Natural Resources.
This isn't the first evidence to suggest that predatory dinosaurs hunted in packs. A set of three Tyrannosaurus rex footprints found imprinted in mud in Canada this past summer also suggest that these guys traveled in gangs. Though most scientists believe these animals to be loners, the study adds to the growing evidence that such ferocious beasts hunted together to increase their chances for bringing down prey, as well as ensure their survival.
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