The "Fighting Dinosaurs" specimen, found in 1971, preserves a Velociraptor mongoliensis and Protoceratops andrewsi in combat and provides direct evidence of predatory behavior. When originally reported, it was hypothesized that the two animals drowned.[11] However, as the animals were preserved in ancient sand dune deposits, it is now thought that the animals were buried in sand, either from a collapsing dune or in a sandstorm. Burial must have been extremely fast, judging from the lifelike poses in which the animals were preserved. Both forelimbs and one hindlimb of the Protoceratops are missing, which has been seen as evidence of scavenging by other animals.[23]
The distinctive claw, on the second digit of dromaeosaurids, has traditionally been depicted as a slashing weapon; its assumed use being to cut and disembowel prey.[24] In the "Fighting Dinosaurs" specimen, the Velociraptor lies underneath, with one of its sickle claws apparently embedded in the throat of its prey, while the beak of Protoceratops is clamped down upon the right forelimb of its attacker. This suggests Velociraptor may have used its sickle claw to pierce vital organs of the throat, such as the jugular vein, carotid artery, or trachea (windpipe), rather than slashing the abdomen. The inside edge of the claw was rounded and not unusually sharp, which may have precluded any sort of cutting or slashing action, although only the bony core of the claw is known. The thick abdominal wall of skin and muscle of large prey species would have been difficult to slash without a specialized cutting surface.[23]
The slashing hypothesis was tested during a 2005 BBC documentary, The Truth About Killer Dinosaurs. The producers of the program created an artificial Velociraptor leg with a sickle claw and used a pork belly to simulate the dinosaur's prey. Though the sickle claw did penetrate the abdominal wall, it was unable to tear it open, indicating that the claw was not used to disembowel prey. However, this experiment has not been published or repeated by other scientists, so its results cannot be confirmed.