A newly discovered fish-eating dinosaur from Argentina may have hunted in a way similar to modern herons, offering fresh insight into the ecosystems of South America during the age of dinosaurs.
Researchers identified the species, named Kank australis, from fossil remains that include teeth, vertebrae, and toe bones recovered in southern Patagonia. The dinosaur lived about 70 million years ago during the Late Cretaceous period.
The species was described by paleontologist Matías Motta and colleagues from the Museo Argentino de Ciencias Naturales Bernardino Rivadavia. Their findings were published in the Journal of Vertebrate Paleontology.
Scientists classified Kank australis as an unenlagiid, a group of raptor-like theropod dinosaurs known from South America, Antarctica, Australia, and Madagascar. Based on comparisons with the related species Neuquenraptor argentinus, researchers estimate the dinosaur grew to between 2.5 and 3 meters (8 to 10 feet) in length.
Ancient rivers shaped its habitat
The discovery site paints a picture of a very different Patagonia from the one seen today.
Researchers said the dinosaur lived among winding rivers, streams, and seasonal ponds surrounded by aquatic plants such as water lilies. The environment also supported fish, insects, and mollusks, creating a rich food source for predators.
Analysis of ancient soils and fossilized plants indicates the region had a temperate and humid climate with seasonal rainfall. Modern Patagonia is much colder and drier by comparison.
Evidence points to a fish-based diet
The fossil remains suggest Kank australis may have been specially adapted for catching fish.
Researchers found that the dinosaur’s neck vertebrae contained structures linked to muscle attachment and the protection of blood vessels. According to Motta, similar features appear in modern birds with highly flexible necks, particularly herons.
Descubren en Argentina un dinosaurio pescador parecido a una garza que vivió hace 70 millones de años.
🦖 Durante décadas, imaginamos a los raptores como veloces cazadores terrestres. Ahora, un hallazgo en la Patagonia argentina nos descubre la existencia de un dinosaurio de… pic.twitter.com/jzTXpsr5Wt— Enrique Coperías (@CienciaDelCope) May 29, 2026
The anatomy likely allowed the dinosaur to make rapid and precise head movements while hunting in shallow water. Researchers believe it spent much of its time near rivers and wetlands, actively pursuing fish rather than hunting primarily on land.
Additional evidence comes from the broader unenlagiid family. Members of the group possessed elongated snouts, numerous teeth, and long, flexible necks, traits often associated with fishing behavior. Fossils of Kank australis were also found alongside fish remains, further supporting the idea that fish formed an important part of its diet.
A hunter that also faced larger predators
Although fish were likely its main prey, the dinosaur shared its habitat with a variety of other animals, including frogs, lizards, turtles, and small mammals.
The ecosystem also contained formidable predators. Among them was Maip macrothorax, a giant megaraptorid dinosaur more than 10 meters (33 feet) long. Researchers said the massive carnivore may have hunted smaller dinosaurs such as Kank australis.
Filling a gap in South America’s fossil record
The discovery has significance beyond the dinosaur’s unusual feeding habits.
Researchers said Kank australis helps fill a major gap in the fossil record of southern Patagonia. The species connects known unenlagiid discoveries from northern Patagonia with those found in Antarctica, suggesting the group was distributed across a wide range of environments and latitudes during the Late Cretaceous.
The name Kank comes from the mythology of the Aonikenk people of Patagonia and refers to a giant rhea associated with a constellation in the sky. The species name, australis, means “southern” in Latin and reflects the location of the discovery.
Researchers plan to continue excavations in the Chorrillo Formation and investigate additional fossils from Patagonia in hopes of learning more about how these fish-eating dinosaurs evolved and spread across ancient South America.
