Scientists have uncovered a fish-hunting raptor from Patagonia that may have stalked prey like a giant prehistoric heron.
A newly identified dinosaur from Patagonia is giving scientists fresh insight into how some raptor relatives lived during the final chapter of the age of dinosaurs. The species, named Kank australis, appears to have spent much of its time hunting fish in rivers and wetlands, using a feeding strategy more reminiscent of modern herons than the fearsome land predators often associated with raptors.
Researchers identified the new species from fossil remains that include teeth, vertebrae, and toe bones. The dinosaur lived roughly 70 million years ago in what is now southern Argentina.
Kank australis belongs to a group called unenlagiids, a family of small to medium-sized theropod dinosaurs known from Late Cretaceous rocks in South America, Antarctica, Australia, and Madagascar. By comparing the new species with Neuquenraptor argentinus, a related dinosaur that lived in northern Patagonia around 90 million years ago, scientists estimate that adult Kank individuals reached lengths of about 2.5 to 3 meters (8 to 10 feet).
The discovery is described in the Journal of Vertebrate Paleontology by Dr. Matías Motta of the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires (Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”) and colleagues.
Ancient Patagonia Was a Wetland Paradise
According to Dr. Motta, Kank inhabited an environment filled with winding rivers, streams, and seasonal ponds.
“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,” says Dr. Motta.
Evidence from fossil plants and ancient soils indicates that southern Patagonia looked very different 70 million years ago than it does today.
“70 million years ago the climate was temperate and humid, with seasonal rainfall, very different from the current cold and relatively dry conditions,” he explains.
A Dinosaur That May Have Hunted Like a Heron
The fossilized bones also offer clues about how Kank behaved.
Researchers found that its neck vertebrae contain specialized structures related to muscle attachment and the protection of blood vessels. Similar features are seen in modern birds that rely on precise and flexible neck movements, particularly herons.
“The cervical vertebrae of Kank show special structures for muscle attachment and the protection of neck blood vessels — features particularly important in modern birds with complex neck movements, such as herons,” says Dr. Motta.
“This suggests Kank may have been an active fisher, contrasting with common portrayal of raptors as agile terrestrial predators, like Velociraptor from the Northern Hemisphere.”
The finding adds to growing evidence that many unenlagiids may have specialized in catching fish rather than hunting primarily on land.
Filling an Evolutionary Gap
The discovery also helps paleontologists better understand how unenlagiids were distributed across South America.
While seven species have previously been identified in northern Patagonia, fossils from the south were too fragmentary to confidently assign to a specific species.
“Kank helps bridge a distributional gap for the Late Cretaceous of southern Patagonia, connecting known records from northern Patagonia and Antarctica, and showing that this family was dispersed across different latitudes of South America.”
The fossils were uncovered at La Anita farm near El Calafate in Argentina’s Santa Cruz Province.
“Field excavations have been conducted there since 2018, uncovering a wide variety of fossil animals and plants,” says Dr. Motta.
The path to identifying the species took several years.
“The first remains of Kank were discovered in 2018, but were too fragmentary to be identified as a new species,” he adds. “Subsequent expeditions recovered additional material, with the discovery of a cervical [neck] vertebra in 2024 proving key to recognising it as a new unenlagiine dinosaur.”
What Made Kank Different?
Like its relatives, Kank australis possessed the enlarged curved claw on the second toe that is commonly associated with raptor-like dinosaurs.
“However,” Dr. Motta says, “it differs in having teeth with sharp and pronounced longitudinal ridges and notably pneumatic cervical vertebrae (with internal air chambers).”
The dinosaur was also more lightly built than some of its later relatives.
“It is also smaller and more gracile compared to other unenlagiids from the end of the Cretaceous, such as Austroraptor cabazai, a giant (around five meters long) unenlagiine from northern Patagonia.”
Evidence for a Fish-Based Diet
Scientists believe Kank was likely a fish eater, adding another piece of evidence supporting the idea that unenlagiids occupied ecological roles similar to modern wading birds.
“Their elongated snouts, numerous teeth and long, flexible necks suggest adaptations for fishing, similar to modern herons,” Dr. Motta explains.
“In the case of Kank, its remains were found alongside fish fossils, reinforcing this idea.”
Still, fish may not have been its only prey. The region was home to frogs, turtles, lizards, and small mammals, any of which could have been potential food sources.
One notable mammal from the area was Patagorhynchus pascuali, a semi-aquatic monotreme related to modern echidnas and platypuses.
Kank also shared its environment with much larger predators.
“Kank coexisted with larger carnivores such as Maip macrothorax, a formidable megaraptorid dinosaur more than 10 meters long, which may have been capable of preying upon it,” Dr. Motta adds.
The Meaning Behind the Name
The dinosaur’s genus name honors a figure from the mythology of the Aonikenk, the southernmost group of the Indigenous Tehuelche people of Patagonia.
“Kank refers to an old giant rhea [a large, flightless South American bird] whose powerful running steps left the imprint of its toes in the sky, forming the constellation known as Choiols,” explains Dr. Motta.
“In Latin, this constellation is called Crux, the Southern Cross — which points toward the southernmost region of the planet, where Kank was discovered.”
The species name australis, meaning “from south,” also reflects the location where the fossils were found.
More Discoveries May Be Ahead
Researchers plan to continue excavations in the Chorrillo Formation, where the fossils were discovered.
“The site where Kank was discovered has provided extensive information about the Late Cretaceous environment of southern Patagonia, so continuing excavations there is crucial,” explains Dr. Motta.
“Finding more Kank fossils will help us better understand its biology and ecological role.”
At the same time, the team is studying fossils recovered from four sites in northern Patagonia.
“These findings indicate that unenlagiids were widely distributed during the Late Cretaceous,” Dr. Motta says.
He adds: “We are particularly interested in investigating the environments they colonized and speciated in — especially in ecosystems dominated by large apex predators such as abelisaurids and megaraptorans.”
Reference: “New unenlagiid from the Chorrillo Formation (Late Cretaceous, Maastrichtian), SW Patagonia, Argentina” by Matías J. Motta, Alexis M. Aranciaga Rolando, Sebastián Rozadilla, Federico L. Agnolín, Federico Brissón Egli, Gerardo P. Álvarez Herrera, Nicolás R. Chimento, Gastón Lo Coco, Takanobu Tsuihiji, Makoto Manabe, Diego Pol and Fernando E. Novas, 28 May 2026, Journal of Vertebrate Paleontology.
DOI: 10.1080/02724634.2026.2656456
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