This 70-million-year-old predator didn’t stalk herds on the plains. Rather, it behaved a lot like a modern heron, a long-necked bird. 

A team of paleontologists led by Dr. Matías Motta of the Bernardino Rivadavia Natural Sciences Museum in Argentina has officially identified the new species. It fills a geographic gap, proving these bizarre raptors ranged far wider into the southern hemisphere than previously known.

Heron-like raptor

The story of its discovery is a lesson in patience. Researchers began unearthing fragments at La Anita farm near El Calafate in Santa Cruz, Argentina, back in 2018. The early bones were too shattered to identify. However, the true breakthrough came recently, when the team recovered a beautifully preserved cervical (neck) vertebra. Other remains included teeth and toe bones. 

That single neck bone changed everything. It was highly pneumatic, riddled with internal air chambers that made it incredibly light. More importantly, it possessed specialized structures for heavy muscle attachment and blood vessel protection. Modern wading birds share this exact design. It allows herons to snap their heads forward with lightning speed to spear fleeing fish.

“This suggests Kank may have been an active fisher, contrasting with the common portrayal of raptors as agile terrestrial predators, like Velociraptor from the Northern Hemisphere,” said Dr Motta. Kank australis belongs to the unenlagiids, a family of small-to-medium theropod dinosaurs discovered across Late Cretaceous deposits in South America, Antarctica, Australia, and Madagascar. 

Researchers estimate that adults of this new species reached lengths of approximately 2.5 to 3 meters (8 to 9 feet).

Ancient Patagonia

The landscape K. australis inhabited looked nothing like the cold, dry Patagonia of today. 70 million years ago, the region was a lush, humid wonderland of meandering streams, seasonal ponds, and floating water lilies.

Kank waded through these shallow waters, using its elongated snout and specialized, ridge-lined teeth to snap up fish.

“Kank lived in a landscape of meandering rivers and streams with seasonal ponds, inhabited by aquatic plants such as water lilies and animals including fish, insects, and various mollusks,” said Dr Motta. 

It was a dangerous life. While Kank was busy stalking fish, frogs, and primitive mammals, it had to keep a sharp eye out for its own predators. It shared the waterways with Maip macrothorax, a terrifying megaraptorid monster stretching over 10 meters long. To survive, the creature relied on its light, slender build to run fast when danger neared. 

Like its raptor relatives, the dinosaur also featured a large, sickle-like claw on its second toe.

The dinosaur‘s name reflects its southern roots. The genus name Kank honors an ancient myth of the indigenous Aonikenk (Tehuelche) people. In the tale, an old, giant rhea ran so powerfully its steps left imprints in the sky, creating the constellation Choiols — known in the West as the Southern Cross. The species name australis simply means “from the south.”

Dr. Motta and his team are already planning further digs into Patagonia’s Chorrillo Formation to understand the past environment and its creatures.

The findings were published in the Journal of Vertebrate Paleontology on May 28. 

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