Austroraptor / Ypupiara / Buitreraptor (Unenlagiinae)

Unenlagiinae was a distinct group of dromaeosaurids from the Late Cretaceous of Patagonia, representing a southern hemispheric lineage of the famous Asian and North American "raptors." These animals possessed light, elongated bodies, long legs adapted for running, and narrow skulls with small, finely serrated teeth, in addition to their long snouts, similar to those of a Borzoi dog—characteristics that indicate diets more specialized in fish and less focused on large prey. Buitreraptor, one of the smallest representatives, likely hunted small vertebrates and possibly aquatic prey, indicating an agile, stealthy lifestyle similar to modern semi-aquatic predators. In contrast, Austroraptor represented the opposite extreme: reaching up to 6 meters in length, it was one of the largest known dromaeosaurids, featuring a long, narrow snout, reduced dentition, and small arms—adaptations that indicate an opportunistic predator capable of taking down medium-sized prey.