What unusual adaptation did the Gorgonopsid have that made it such a dominant predator?

Gorgonopsia is an extinct clade of non-mammalian synapsids from the Permian period. Gorgonopsians were quadrupedal predators with prominent canine teeth, and the largest species were the apex predators of their ecosystems.[1] Like other non-mammalian synapsids, gorgonopsians were once described as "mammal-like reptiles", due to their mix of mammalian and reptilian traits. However, this description is no longer considered accurate as they are not reptiles.[2] Rather, as therapsids, they are closely related to mammals. Gorgonopsian fossils have been found in Russia and Africa.[3]