The real answer is none, but gregarious behavior, which is not always equal to pack-hunting, is a different story. So what theropods popularly depicted as pack hunters actually may have been social?
Deinonychus - The famous Tenontosaurus site, which Osborn initially interpreted as the result of a hunt from the dromaeosaur on the iguanodontian, was most likely a killsite where aggressive feeding frenzies
Tale told by the cracked, flaky surface of a nearby riverbed. All around, occasional clusters of drying trees are scattered across the dusty terrain. Along the fringes of one such island of tall vegetation, three elephantine Cathartesaura search for whatever food is available, two of them craning their swan-like necks high among the dead branches for dwindling greenery while the third wanders off to examine the ground underfoot. Whistles and cracks from their tails flicking through the air at sound barrier-breaking speeds help the trio keep in contact, along with deep chest rumbles sent and felt through their feet.
Sweeping its long neck across the barren dirt, the Cathartesaura scours the plains for sustenance. Its nose picks up something moist underneath the dry soil.
Digging with its snout, the whiptail uproots a cluster of tender roots. It’s not much of a meal considering the large quantities of vegetation neede