Fish-eating raptor from 70M years ago discovered in Patagonia

Seventy million years ago, in what is now southern Patagonia, a small dinosaur waded through meandering rivers and seasonal ponds, hunting fish with the deliberate grace of a modern heron. Paleontologists have now given this creature a name: Kank australis. The discovery, announced in the Journal of Vertebrate Paleontology, rests on fossil remains—teeth, vertebrae, and toe bones—unearthed at La Anita farm near El Calafate in Argentina's Santa Cruz province. The first fragments surfaced in 2018, but it took six years and the recovery of a crucial neck vertebra in 2024 before researchers could identify the animal as a previously unknown species.

Kank australis belongs to the unenlagiids, a family of small-to-medium theropod dinosaurs that roamed South America, Antarctica, Australia, and Madagascar during the Late Cretaceous. Comparison with a related species, Neuquenraptor argentinus from northern Patagonia, suggests Kank adults reached between 2.5 and 3 meters in length—considerably smaller than some of its cousins, particularly Austroraptor cabazai, a 5-meter giant from the same northern region. The new species is described by Dr. Matías Motta of the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires and his colleagues.

The landscape where Kank lived bore little resemblance to Patagonia today. Ancient soil samples and fossilized plant remains tell of a temperate, humid climate with seasonal rainfall, dotted with water lilies and teeming with fish, insects, mollusks, frogs, lizards, and turtles. The cervical vertebrae of Kank reveal specialized structures for muscle attachment and blood vessel protection—features found in modern birds like herons that execute complex neck movements. This anatomy, combined with the dinosaur's elongated snout, numerous teeth, and flexible neck, points to an active fisher rather than the agile terrestrial predator that Velociraptor represents. Kank fossils were discovered alongside fish remains, reinforcing the picture of a specialized aquatic hunter.

Yet Kank was not alone in this ecosystem, and not necessarily at the top of the food chain. The animal coexisted with larger carnivores, including Maip macrothorax, a megaraptorid dinosaur exceeding 10 meters in length that may have hunted Kank itself. The smaller raptor shared its world too with Patagorhynchus pascuali, a semi-aquatic monotreme related to modern echidnas and platypuses. Like other unenlagiids, Kank possessed an enlarged, raptorial claw on the second toe of each foot. But it differed from its relatives in key ways: its teeth bore sharp, pronounced longitudinal ridges, and its cervical vertebrae were notably pneumatic, containing internal air chambers that reduced weight while maintaining structural strength.

The naming of Kank australis draws from Patagonian indigenous lore. The Aonikenk, the southernmost group of the Tehuelche people, told of an ancient giant rhea whose powerful running steps left imprints in the sky, forming what is now known as the Southern Cross constellation—Crux in Latin. Kank references this mythological creature, while australis, meaning "from the south," marks the latitude of discovery. The species name thus anchors the dinosaur to the landscape and sky of its homeland.

The discovery fills a significant gap in the fossil record. Seven unenlagiid species have been documented in northern Patagonia, but southern Patagonia had yielded only scattered, unidentifiable remains. Kank bridges that distributional gap, connecting known records from the north with those from Antarctica and demonstrating that the family was dispersed across different latitudes of South America. Dr. Motta and his team are planning further excavations at the Chorrillo Formation, the geological layer where Kank was found. They are also studying new fossils from four sites in northern Patagonia, seeking to understand which environments these fish-eating raptors colonized and how they speciated—particularly in ecosystems dominated by the apex predators that may have hunted them.