Austroraptor

## AustroraptorSouthern Thief

* Adult Variant 1
* Adult Variant 2
* Sub-adult Male

* **Skull Length** of 80 centimeters (2 feet, 7 inches)
* **Femur Length** of 56 centimeters (1 foot, 10 inches)
* **Arm Length** of 26 centimeters (10.24 inches)
* Teeth are conical, non-serrated, and have fluted enamel surfaces, much like those of spinosaurids

***Austroraptor*** (Southern Thief) is a genus of unenlagiine dromaeosaurid that lived in the Allen Formation, Argentina, 72 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

## Description

### Size and Physique

***“ A ferocious, three foot-long garfish... lunch, for a giant Austroraptor. They are relatives of Velociraptors, but much, much bigger. Twenty feet from head to tail, and weighing over 800 pounds. ”***

― **David Attenborough**, *Swamps*
With a length of 5 - 6 meters (16 - 20 feet), *Austroraptor* is one of the largest dromaeosaurids known, with only *Utahraptor* and *Achillobator* (as well as *Imperobator*, should the 2023 suggestion that it is a large unenlagiine like *Austroraptor* receive more support) approaching or surpassing it in length. Earlier estimates of its weight go as far as 300 kilograms (660 pounds), while more recent estimates suggest that its weight was equivalent to that of a lion, at 91 - 227 kilograms (201 - 500 pounds). On Prehistoric Planet, it is stated that *Austroraptor* can weigh over 363 kilograms (800 pounds).

### Fishing Adaptations

***“ And with teeth not unlike those of a crocodile, these dinosaurs are very skilled at catching fish. ”***

― **David Attenborough**, *Swamps*
*Austroraptor*, much like all unenlagiine dromaeosaurs, has a more gracile build and longer legs compared to more recognizable Laurasian eudromaeosaurians like *Dromaeosaurus*. Its arms, being approximately 46% the length of its femur, are proportionally shorter than those of other dromaeosaurs (indicating that it didn't use its arms to handle prey), as well as reduced sickle claws on its feet (it should be noted, however, that the sickle claws were originally meant to be more strongly curved and pointed as indicated by preserved keratin sheaths, but filming constraints unfortunately prevented changes from being made to the animal's digital model). These traits, along with a long, low, narrow snout filled with conical, non-serrated teeth much like those of a crocodile, suggest that it lived a primarily piscivorous lifestyle much like spinosaurids, fishing in a manner similar to that of herons.

### Prehistoric Planet's Depiction

***“ For those not yet in their prime, it's a challenging time of year. This young male, still in his juvenile colors, has little hope of securing a place to fish. ”***

― **David Attenborough**, *Swamps*
On Prehistoric Planet, the *Austroraptors* are designed using a skeletal base made by Dr. Scott Hartman, with their large pygostyles (tail fans) based on the art of David Krentz. Given the size of these tail fans, a lot of considerations were made regarding how the tails of the *Austroraptors* interacted with parts of the environment they were filmed in (Great Otway National Park in Victoria, Australia), like tree ferns and other plants.

The *Austroraptors* are depicted with a color scheme of brown and yellowish-white tones, with the brown parts likely inspired by the fact that their lifestyle is comparable to those of grizzly bears. The upper sides of their bodies, the area around their eyes, and their snouts are brown, while their undersides, eyebrows, the rest of their faces, the edges of the wing-like feathers on their short arms, and the edges of their pygostyles are yellowish-white. Interestingly, their eyes are portrayed as having a human-like appearance, with large pupils. Some individuals, particularly those with a deeper shade of brown and slightly more robust builds, also have red patches below and behind their eyes. Dr. Darren Naish, lead consultant of Prehistoric Planet, brings up that this is not a sign of sexual dimorphism, but a trait that is more likely to be seen on some (but not all) adults. Sub-adults appear to still have their juvenile plumage, which comes in a lighter shade of brown with some yellowish-white specks.

## Habitat

***“ Here in the wetlands of South America, long summer days are fueling a greater feast. These swamps are teeming with animals of all kinds... and hunters are gathering. ”***

― **David Attenborough**, *Swamps*
*Austroraptor* is known from the Allen Formation in Argentina, South America, a semi-arid environment heavily eroded by winds (partly due to large storms in the region), with landscapes that range from estuaries and tidal flats by the coastal regions to lakes and rivers further inland, providing many fishing opportunities for *Austroraptor*. On Prehistoric Planet, *Austroraptors* are shown fishing on the banks of a shallow river running through a lush forest.

## Behavior

Most of *Austroraptor's* behavior on Prehistoric Planet is based on the observed habits of modern-day herons, bears, crocodiles, and eagles.

### Competitive Habits

***“ For most of the year, they're solitary hunters. But, as the number of fish increases during summer, so does the number of Austroraptors. The biggest try to keep the best fishing spots for themselves. They won't tolerate rivals. ”***

― **David Attenborough**, *Swamps*
While *Austroraptors* are usually solitary hunters, they take advantage of the increase in fish numbers during summer and congregate around bodies of water to capitalize on this abundant food supply. However, this does not make them any more social. Not all fishing spots are equally fruitful, leading to competition among the *Austroraptors*. The show depicts them as willing to engage in fights over these preferred fishing spots, emphasizing their competitive nature and the significance of securing the most advantageous hunting grounds.

### Feeding Preferences

***“ With so much food around, the adults are very wasteful feeders. They often eat only the choicest parts of the fish. And for the youngster, any leftovers will do very nicely... but it's risky. To succeed, he will have to be sneaky. ”***

― **David Attenborough**, *Swamps*
The adult *Austroraptors* are shown indulging in wasteful eating habits when fish are abundant. They tend to consume only the most desirable portions of the fish, often tearing off and quickly devouring the back half while leaving the other half behind. This behavior results in a significant amount of leftover food on the ground. Young *Austroraptors*, motivated by the need for sustenance, scavenge these remnants as it presents an opportunity to obtain a meal, even if what they obtain is nothing more but a few scraps. However, they are opportunistic and would take advantage of any situation that allows them to acquire more than just leftovers.

## Appearance

**Swamps**, Segment II
**Setting**
Allen Formation, Neuquén, Río Negro, and La Pampa Provinces, Argentina

**Filming Location**
Great Otway National Park, Victoria, Australia
In the second segment of Swamps, an *Austroraptor* is seen snatching a 1-meter (3-foot) garfish out of the river, stomping it down on the ground to rip off and devour only the lower half of the fish. Since it is summer, when many fish are present, a large number of *Austroraptors* are found gathering all over a shallow river, with some fishing by the banks and others fishing in the middle of the river. One *Austroraptor* senses a larger, more robust individual with red eye patches sneaking up behind it, intent on taking its fishing spot, and turns around to snarl back at the trespasser. The two individuals hiss and growl at each other before the owner of the fishing spot, being slimmer, is forced to back away.

For the younger ones who haven't established their fishing spot nor have enough experience to find a good place to fish, this is a challenging time of year. A young adult male, still in his juvenile colors, attempts to fish from atop a log, but this is suspended too high over the river. Upon seeing the other *Austroraptors* rip off only the lower half of their catch, the youngster tries to sneak in and grab the discarded upper half of the fish while one of the adults is busy catching and feeding on another fish. Unfortunately, his attempt wasn't stealthy enough, and the adult notices him and attacks him, forcing the young male to retreat back behind a tree.

***“ Bruised and empty handed. But with the adults still feasting around him, there might be another opportunity. Two adults, fighting over the best fishing spot. Time for the youngster to make a move... and time to leave. ”***

― **David Attenborough**, *Swamps*
The youngster then sees two adults fighting over a fishing spot, and, as one adult chases the other into the forest, he sneaks in to steal the latest catch of one of them, a fully-intact garfish lying on the ground. He grabs it and runs off just as the owner of the fishing spot rushes back in to attack him, getting away in a nick of time as the adult slips on the ground.

***“ Success, and more than just scraps. A lesson learnt. And when the good conditions return next year, perhaps he'll be able to challenge for a fishing spot of his own. ”***

― **David Attenborough**, *Swamps*
Needing all the food he can get, the young *Austroraptor* looks around warily one last time before swallowing the entire fish. While he resorts to opportunistic thievery now, perhaps, when fishing season returns next year, he can properly challenge one of the adults for a good fishing spot of his own.

## Trivia

The second segment of Swamps is the seventh segment to feature intraspecific combat, and is the fourth one to result in the older individual emerging triumphant (assuming that those with the red patches behind their eyes are older).

## References

### General

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 A bizarre Cretaceous theropod dinosaur from Patagonia and the evolution of Gondwanan dromaeosaurids
2. ↑ 2.0 2.1 *The Princeton Field Guide to Dinosaurs*
3. ↑ 3.0 3.1 Holtz Dinosaur Genus Appendix
4. ↑ Phylogenetic relationships of *Austroraptor cabazai*
5. ↑ New Insights into Unenlagiine (Theropoda: Paraves: Dromaeosauridae) Diversity, Paleoecology, and Paleobiogeography Derived from Late Cretaceous Fossils from Patagonia and Antarctica

### Dr. Darren Naish

1. ↑ 1.0 1.1 1.2 1.3 *Austroraptor* is depicted fishing in a heron-like style, and there was a plan to trick the audience into thinking that its segment was going to be about a spinosaur-type dinosaur, only for it to be revealed that the focus is a relative of *Velociraptor*. It's been suggested by series producer Alec Ginns that these dromaeosaurs, around 5 meters (16 feet) long, may have congregated where and when fishes were plentiful, much like bears, bald eagles, and crocodiles do today. Such gatherings can result in conflict, thievery, and scavenging, as has been observed in herons and eagles.
2. ↑ The sickle toe of *Austroraptor* was supposed to be more strongly curved and pointed as indicated by preserved keratin sheaths, but the manufacturing of a physical leg and foot prop (that ultimately went unused because it didn't look real enough) prevented any further changes from being made to the digital model of *Austroraptor*.
3. ↑ A lot of work was done to get the feathering, snout, and eyes to look right for an animal the size of *Austroraptor*. Dr. Scott Hartman designed *Austroraptor's* skeletal base, and the tail was designed based on the art of David Krentz. The size of *Austroraptor's* tail fan ended up causing some issues, as the filming team had to take into account how it interacted with the tree ferns and other plants present in the Australian location chosen to represent the Argentinian region where *Austroraptor* lived in.
4. ↑ The red eye patches of the *Austroraptors* are not a sex-exclusive trait, but a variable trait, with their pigmentation influenced by age.
5. ↑ At least a dozen color variants for *Austroraptor* were designed by David Krentz, resulting in noticeable differences and variations in plumage and red facial markings.

### Prehistoric Planet

1. ↑ 1.0 1.1 1.2 1.3 As stated in Swamps.
2. ↑ 2.0 2.1 2.2 I Know Dino: The Big Dinosaur Podcast, Episode 445: Dinosaurs in Swamps: Featuring Prehistoric Planet 2