Austroraptor cabazai
Austroraptor was one of the largest dromaeosaurids ever found, and it looked nothing like the popular image of a "raptor". The animal reached about 5–6 metres in length and probably weighed between 250 and 500 kilograms.
Austroraptor
Austroraptor cabazai
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Weight
250–500 kg
Length
5–6 m
Diet
Piscivore
Period
Cretaceous
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250–500 kg
5–6 m
Cretaceous
Bipedal
1.4–1.8 m
Piscivore
2 recorded fossil finds in Argentina. First described in 2008 by Novas et al..
Sites and counts from the Paleobiology Database
The timeline shows the whole age of dinosaurs – and how much time has passed since. The glowing part is when Austroraptor lived.
million years ago
Lived 75–70 million years ago
If the whole age of dinosaurs were a single day, Austroraptor lived at 23:10.
Chapter • Meet the dinosaur
Austroraptor was one of the largest dromaeosaurids ever found, and it looked nothing like the popular image of a "raptor". The animal reached about 5–6 metres in length and probably weighed between 250 and 500 kilograms. Its skull was unusually long and low – roughly 80 centimetres – recalling the head of a gharial or a spinosaur far more than the short, deep snout of Velociraptor. The teeth were small, conical and lacked the serrated edges typical of most meat-eating dinosaurs. Strangest of all were the arms: they were markedly shortened relative to the body, which is highly unusual within the dromaeosaurid family. Like all close relatives of birds, Austroraptor almost certainly bore a covering of feather-like structures, and it walked upright on two legs with the body held horizontally and balanced by a stiffened tail. Austroraptor belongs to the unenlagiines, a South American branch of the dromaeosaurids that evolved in relative isolation after the break-up of Gondwana. Like its relatives it had a flexible, S-curved neck and an enlarged claw on the second toe, though that sickle claw was less formidable than in northern cousins such as Deinonychus. The combination of short arms, elongated jaws and slender, pointed teeth is read by most researchers as an adaptation to catching slippery prey – in other words, fish. The long jaws could snap shut quickly, while the conical teeth gripped without slicing. Its diet therefore probably consisted largely of fish taken from the rivers and floodplains where it lived, supplemented by small vertebrates, juvenile dinosaurs and possibly carrion. It should be stressed that no gut contents or preserved last meal are known for Austroraptor; the interpretation rests on tooth and skull shape and on comparison with living fish-eating animals. Some palaeontologists point out that a five-metre predator would hardly have been fussy and would have taken whatever prey was available. The first bones were found in 2002 by a team led by the Argentine palaeontologist Fernando Novas at Bajo de Santa Rosa in the Allen Formation, Río Negro Province, Argentina. The species was formally described in 2008. The genus name means roughly "southern thief", while the species name cabazai honours Alberto Cabaza, founder of the municipal museum in Lamarque. The material includes parts of the skull, neck vertebrae, ribs and limb bones – enough to show that Southern Hemisphere dromaeosaurids followed a distinctly different evolutionary path.
Chapter • Where it lived
Austroraptor lived about 75–70 million years ago, in the Late Cretaceous (late Campanian to early Maastrichtian), in what is now northern Patagonia. The fossils come from the Allen Formation at Bajo de Santa Rosa, Río Negro Province, Argentina. The landscape was one of floodplains, meandering rivers, lakes and lagoons close to an advancing seaway, with dune fields and salt-influenced flats further inland. Austroraptor shared this world with titanosaurian sauropods such as Rocasaurus and Bonatitan, hadrosaurs, smaller theropods and a rich fauna of fish, turtles and crocodyliforms.
Chapter • Wild behavior
Cathemeral
Every known specimen of Austroraptor represents an isolated individual, and there are no trackways, bonebeds or other direct evidence that the species lived or hunted in groups. The familiar idea of "pack-hunting raptors" is based on debated finds of entirely different species in the Northern Hemisphere and cannot simply be transferred here. Most researchers therefore assume Austroraptor was largely solitary, perhaps gathering temporarily at rich food sources, but this remains an informed inference rather than an established fact.
Austroraptor is among the largest dromaeosaurids known, rivalled only by Utahraptor and Dakotaraptor.
Its skull was about 80 centimetres long yet narrow and low, rather like that of a gharial.
Its arms were proportionally very short for a dromaeosaurid, earning it the nickname "the T. rex of raptors".
The teeth were conical and unserrated, a feature otherwise seen in fish-eaters such as spinosaurids and crocodilians.
The species name cabazai honours Alberto Cabaza, who founded the museum in the Argentine town of Lamarque.
It belonged to the unenlagiines, a group known only from former Gondwana, and above all from South America.
Austroraptor lived right at the end of the age of dinosaurs, only a few million years before the mass extinction 66 million years ago.
Like other feathered maniraptorans of its size, Austroraptor could not fly – its body was far too large and its arms far too short.
Chapter • Scientific place
Proceedings of the Royal Society B: Biological Sciences
Reviewed: 9/6/2026
Original description by Novas, Pol, Canale, Porfiri & Calvo that erects Austroraptor cabazai and places it within Dromaeosauridae (Unenlagiinae) among Gondwanan paravians.
Open sourcePaleobiology Database
Reviewed: 9/6/2026
Records the holotype MML-195, its type locality in the Allen Formation of Río Negro Province, Argentina, and the Campanian–Maastrichtian stratigraphic occurrence data for the taxon.
Open sourcePLOS ONE
Reviewed: 9/6/2026
Documents the geological setting and fluvial–coastal palaeoenvironment of the Allen Formation of Río Negro Province, the unit in which Austroraptor was found.
Open sourceHistorical Biology (Taylor & Francis)
Reviewed: 9/6/2026
Analyses the cranial and dental morphology of Austroraptor, whose conical, unserrated teeth and elongate snout support fish-eating (piscivorous) feeding habits shared with other unenlagiids.
Open sourceActa Palaeontologica Polonica
Reviewed: 9/6/2026
Extinct taxon; conservation status NE
Open sourceProceedings of the Royal Society B: Biological Sciences
Reviewed: 9/6/2026
The peer-reviewed paper that first described Austroraptor cabazai, covering its anatomy, body size, age and provenance, used as the general overview source for the sv, en, da and no descriptions.
Open sourceProceedings of the Royal Society B: Biological Sciences
Reviewed: 9/6/2026
The peer-reviewed paper that first described Austroraptor cabazai, covering its anatomy, body size, age and provenance, used as the general overview source for the sv, en, da and no descriptions.
Open sourceProceedings of the Royal Society B: Biological Sciences
Reviewed: 9/6/2026
The peer-reviewed paper that first described Austroraptor cabazai, covering its anatomy, body size, age and provenance, used as the general overview source for the sv, en, da and no descriptions.
Open sourceProceedings of the Royal Society B: Biological Sciences
Reviewed: 9/6/2026
The peer-reviewed paper that first described Austroraptor cabazai, covering its anatomy, body size, age and provenance, used as the general overview source for the sv, en, da and no descriptions.
Open source