Kank australis: The Heron-Like “Wetland Raptor” – Master Fish-Hunter from Late Cretaceous Patagonia!

Paleontologists have unveiled Kank australis, a newly described unenlagiid theropod from the Maastrichtian Chorrillo Formation (~70 million years ago) in southern Santa Cruz, SW Patagonia, Argentina. The discovery, published online May 28, 2026, in the Journal of Vertebrate Paleontology, reveals a specialized predator that stalked freshwater wetlands—adding powerful evidence that some southern raptors evolved heron-like hunting strategies.

Recovered from fluvial sediments at La Anita farm, the holotype comprises a highly pneumatized cervical vertebra with prominent parapophyses and carotid processes, pedal phalanges (including a troodontid-like II-2 with reduced condyles), and shed teeth. These features distinguish K. australis from northern Patagonian relatives such as Unenlagia and Neuquenraptor. Adults likely reached 2.5–3 meters long—compact yet agile, with elongate snouts, tiny teeth, and bird-like arms supporting feathered wings.

Lead author Matías J. Motta and colleagues interpret the anatomy as adaptations for wading and fish-catching: lightweight pneumatized bones for maneuverability in flooded terrain, and denтιтion suited to snatching slippery prey. “This specimen reinforces that Unenlagiidae was a morphologically disparate clade capable of exploiting wetland niches,” the team writes.

The find bridges a critical gap in unenlagiid evolution during the final stages of the Cretaceous, when Patagonia’s lush river systems teemed with fish, turtles, and crocodyliforms. Named after the greater rhea (kank in Tehuelche) and “southern” (australis), it evokes a feathered egret stalking the shallows—far from the classic Velociraptor image.

As more Chorrillo material emerges, Kank australis promises to illuminate how these southern “raptors” thrived in dynamic wetland ecosystems right up to the end-Cretaceous extinction. A true specialist reborn from Patagonia’s ancient floodplains.