A recent discovery in paleontology has unveiled a fascinating dinosaur species, Kank australis, which exhibits hunting behaviors akin to those of modern herons. This revelation stems from the analysis of fossilized remains, including teeth, vertebrae, and toe bones, classified within the unenlagiid family--small to medium-sized theropods known from Late Cretaceous deposits across regions like South America, Antarctica, Australia, and Madagascar.
Researchers, led by paleontologist Dr. Matías Motta from the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires, estimate that adult Kank australis could reach lengths of approximately 2.5 to 3 meters (8 to 10 feet). The findings were published in the Journal of Vertebrate Paleontology.
Life in Ancient Patagonian Wetlands
Dr. Motta describes the habitat of Kank as a lush landscape characterized by winding rivers, streams, and seasonal ponds, abundant with aquatic vegetation, including water lilies, alongside various fish and mollusks. "Seventy million years ago, this region had a temperate and humid climate, a stark contrast to today's colder, drier conditions," he elaborates.
A Dinosaur Adapted for Fishing
The fossilized remains reveal unique adaptations in Kank's neck vertebrae, which served as muscle attachment points and protected vital blood vessels. These features are reminiscent of modern birds that require precise neck movements for hunting. "This suggests that Kank may have been an adept fisher, diverging from the typical image of raptors as swift land predators," notes Dr. Motta.
Filling a Fossil Record Gap
This discovery bridges a significant gap in the fossil record of unenlagiids across South America, with previous findings from northern Patagonia and few identifiable fossils from the south. "Kank connects these known records, indicating a broader geographical distribution of this family," Dr. Motta explains.
Excavations at La Anita farm near El Calafate, Argentina, have been ongoing since 2018, revealing a wealth of fossils. Initial discoveries were too fragmentary for classification, but subsequent finds, particularly a cervical vertebra in 2024, were pivotal in identifying Kank as a new species.
Distinctive Features of Kank australis
Similar to other unenlagiids, Kank australis features an enlarged claw on its second toe, yet it is distinguished by its sharp, ridged teeth and lightweight build compared to larger relatives. "These traits suggest a specialization in fish-catching," Dr. Motta asserts.
Inspired by Indigenous Patagonian Mythology
The name Kank pays homage to the Aonikenk people, an Indigenous group of Patagonia. It references a giant rhea whose footprints are said to have formed the constellation Crux, or the Southern Cross, which points to the region of discovery.
Looking Ahead
Continuing excavations in the Chorrillo Formation are essential for further understanding the Late Cretaceous ecosystem of southern Patagonia. "By uncovering more fossils, we aim to deepen our understanding of Kank's biology and ecological role," concludes Dr. Motta.