A team of scientists from Argentina and Japan has described a new species of unenlagiid dinosaur from southern Patagonia. Named Kank australis, this small, theropod dinosaur lived around 70 million years ago during the Late Cretaceous.
The fossil remains were discovered in the Chorrillo Formation of Santa Cruz Province, Argentina. The discovery helps palaeontologists better understand the diversity of Southern Hemisphere dromaeosaurids and provides fresh insights into the ecosystems that existed shortly before the extinction of the non-avian dinosaurs.

Kank australis life reconstruction. Picture credit: Gabriel Díaz Yantén.
Picture credit: Gabriel Díaz Yantén
Kank australis Expands the Known Range of Unenlagiids
The newly described Kank australis belongs to the Unenlagiidae, a group of long-snouted paravian theropods up to now represented in Gondwanan landmasses. These dinosaurs are often compared to famous Northern Hemisphere relatives such as the dromaeosaurid Velociraptor. However, unenlagiids were unique to the southern continents. Unenlagiids are particularly diverse in northern Patagonia, where at least seven species have been identified from Upper Cretaceous strata. Therefore, the discovery of Kank australis extends the known distribution of these dinosaurs much further south.
A new fish-eating unenlagiid from Brazil (Ypupiara lopai): A New Piscivorous Dinosaur is Described.
Researchers suggest that this discovery helps bridge an important geographical gap. Furthermore, it may provide clues about links between South American dinosaurs and species that may have inhabited Antarctica during the Late Cretaceous. Antarctic species such as the probable unenlagiid Imperobator antarcticus.
The fossil material consists of vertebrae, isolated pedal phalanges, and shed teeth.

Fossil material associated with the newly described unenlagiid K. australis. Picture credit: Ignacio García.
Picture credit: Ignacio García
Named After an Ancient Mythological Bird
This dinosaur’s name has an interesting origin. The genus name comes from the “elder rhea” from indigenous Aonikenk (Tehuelche) mythology. According to tradition, this bird left its footprint in the sky, creating the constellation known today as the Southern Cross.
Meanwhile, the species name “australis” means southern. It refers to the location in Patagonia where the fossil material was discovered.
Fossils Recovered During Difficult Fieldwork
The remains of Kank australis were collected during several expeditions that began in 2019. One of the most significant discoveries came just before severe weather forced researchers to abandon a field season. A vertebra from the base of the neck was spotted by a technician searching for small fossil fragments. At first, the team could not identify the specimen because it remained embedded in rock. However, once the surrounding matrix was removed, the researchers realised they had found part of a “raptor” dinosaur.

Working on the fossil material. Picture credit: Ignacio García.
Picture credit: Ignacio García
Although fragmentary, the fossils possess distinctive anatomical features that justify the erection of a new species. In addition, the fossils demonstrate a suite of characteristics suggesting that K. australis was probably distinct from other unenlagiids. Therefore, it reinforces the hypothesis that the Unenlagiidae was a morphologically disparate clade.
To read an article from 2024 about a newly described unenlagiine from northern Patagonia (Diuqin lechiguanae): A New Unenlagiid from Northern Patagonia.
What Did It Look Like?
Scientists estimate that Kank australis measured approximately two metres in length. This would make it comparable in size to Velociraptor. Its anatomy suggests that it may have occupied a different ecological niche from many Northern Hemisphere dromaeosaurs. For example, its teeth possess small longitudinal ridges. These structures may have helped the animal grip slippery prey. As a result, researchers propose that fish formed an important part of its diet. Whereas, most Northern Hemisphere dromaeosaurids are thought to have been terrestrial predators.
In addition, the neck vertebrae show specialised muscle attachment sites and structures associated with blood vessel protection. Similar features are seen in modern birds that make complex neck movements, including herons.
Consequently, palaeontologists suggest that Kank australis may have been a piscivore, rather than a purely terrestrial predator.
A Rich Late Cretaceous Ecosystem
Seventy million years ago, Patagonia looked very different from today. The Andes Mountains had not yet formed. Instead, the region was dominated by rivers, lakes and lush vegetation. The Chorrillo Formation has yielded a remarkable range of fossils. These include fish, frogs, turtles, snakes, mammals and numerous dinosaurs.
Large predators also shared this environment. Fossils of the giant megaraptoran theropod Maip macrothorax have been found at the same locality. In addition, the long-necked titanosaur Nullotitan glaciaris roamed the landscape.

A replica of the giant South American theropod M. macrothorax. The CollectA Deluxe Maip macrothorax model measures 26 cm in length.
The picture (above) shows the CollectA Deluxe Maip macrothorax dinosaur model. It is a recent theropod introduction into this extensive scale model range.
To view the CollectA Deluxe models: CollectA Deluxe Prehistoric Animal Models.
Together, these discoveries are helping scientists reconstruct one of the southernmost dinosaur ecosystems known from the final stages of the Age of Dinosaurs.
A Window into the Last Days of the Dinosaurs
The discovery of Kank australis demonstrates that southern Patagonia supported a diverse dinosaur fauna shortly before the end-Cretaceous mass extinction.
Each new fossil helps researchers piece together the complex history of life in Gondwana. Furthermore, discoveries such as Kank australis highlight how much remains to be learned about dinosaur evolution in the Southern Hemisphere.
Everything Dinosaur acknowledges the assistance of a media release from the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” in the compilation of this article.
The scientific paper: “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 published in the Journal of Vertebrate Paleontology.
The Everything Dinosaur website: Theropod Dinosaurs and Other Models.