Atrociraptor

AtrociraptorSavage Thief
Classification
Domain	Eukaryota
Kingdom	Animalia
Phylum	Chordata
Subphylum	Vertebrata
Superclass	Tetrapoda
Clade	Sauropsida
Class	Reptilia
Clade	Archosauria Avemetatarsalia Ornithodira Dinosauria Saurischia Theropoda Neotheropoda Averostra Tetanurae Orionides Avetheropoda Coelurosauria Maniraptoriformes Maniraptora Paraves Eumaniraptora
Family	Dromaeosauridae
Clade	Eudromaeosauria
Subfamily	Saurornitholestinae
Species	Atrociraptor marshalli
Presence
Location	Horseshoe Canyon Formation, Alberta, Canada
Temporal Range	68.5 million years ago, Maastrichtian Stage, Late Cretaceous Period
Episodes	Forests (Segment 5)
Characteristics
Height	60 centimeters (2 feet)
Length	2 meters (6 feet, 7 inches)
Mass	15 kilograms (33 pounds)
Diet	Carnivorous
Has a boxy head Has less variation in tooth anatomy compared to relatives

Atrociraptor (Savage Thief) is a genus of saurornitholestine dromaeosaurid theropod dinosaur that lived in the Horseshoe Canyon Formation in southwestern Alberta, Canada, 68.5 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

Paleobiology

Currently only known from parts of the skull (namely, both premaxillae, the right maxilla, teeth, and parts of the lower jaw), Atrociraptor is believed to be a small saurornitholestine dromaeosaur, only 2 meters (6 feet, 7 inches) long and 15 kilograms (33 pounds) in weight. It had a boxy head (unusually tall with a short, deep snout) and isodont dentition, for its teeth, relatively straight yet emerging from their sockets at an angle (resulting in strongly raked rows of teeth), came in different sizes but more or less shared the same form, distinguishing it from other dromaeosaurs like Bambiraptor, which had more varied forms of teeth.

On Prehistoric Planet, Atrociraptor is depicted with a thick, feathery coat in shades of red, brown, and gold, resembling those of some eagles, with lighter-colored feathers lining its arms and pygostyle (tail fan). Its snout is also bare, revealing the dark scales beneath. Like the unidentified Alaskan troodontid, Dromaeosaurus, and Imperobator, Atrociraptor is portrayed with legs that are heavily-feathered like those of a booted eagle, in contrast with other paravians in the series like Velociraptor, which have bare legs. This trait is likely an adaptation for the cold environment it lived in, or, conversely, the heat of the forest fires that frequently occur in the region during summer.

Paleoecology

Paleoenvironment

Main: Horseshoe Canyon Formation

Main: Horseshoe Canyon Formation

“ In the forests of North America, there is an additional annual hazard for forest-dwellers. Fire, started by a strike of lightning. As it spreads, temperatures rise to over 2000 degrees Fahrenheit. The flames rise several hundred feet into the air. ”

― David Attenborough, Forests

Atrociraptor lived 68.5 million years ago in the Horseshoe Canyon Formation in southwestern Alberta, Canada, which by that time was an area of floodplains and estuaries. Coal swamps in the region indicated that riparian (waterside) forests thrived in such environments, though, as the show depicts, these places were vulnerable to the threat of fires started by factors like dry seasons or thunderstorms. Even so, in the aftermath of such disasters, several plants and animals can take advantage of the scorched land and what remains within.

Feeding Preferences and Ingenuity

“ This Atrociraptor is an opportunist. Quick to return when there's food on offer. And there's something else to be gained here. Smoke is an insecticide, and it can help an animal to get rid of its parasites... but you do have to be careful. ”

― David Attenborough, Forests

Taking advantage of the newly-burned forest, Atrociraptor was one of the first animals to return to the ravaged landscape, eating up beetles that came back to the forest to lay their eggs within the abundant dead wood that will serve as food for their young. Atrociraptor also shows some ingenuity in that it picks up a smoking stick and uses the smoke emanating from it to kill or drive off any parasites in its feathery coat (based on similar behavior exhibited by modern-day birds, which use ash, smoke, or fire to possibly get rid of the parasites on them), though it did exhibit some caution given how the stick is still hot to the touch. When disturbed by a large presence, like a two-tonne Anodontosaurus, the Atrociraptor flees, once again showing caution, presumably running off to another place where it can do what it wants in peace.

Appearance

The fifth segment of Forests is set on a lush mountainside of the Horseshoe Canyon Formation, set alight by a strike of lightning. Hours after the disaster, however, animals returned to make the most of resources and opportunities that follow a forest fire. Beetles arrive to lay their eggs (for larvae would feast on the near-limitless supply of dead wood). An Atrociraptor, taking advantage of the situation, feeds on one of the beetles, and picks up a smoking twig to rid itself of parasites. Sensing a large animal coming close, the Atrociraptor flees the scene as a two-tonne Anodontosaurus arrives to feed on a newly-burned tree stump to help aid digestion by purifying its stomach, the toxins of the many plants it ate neutralized by the charcoal it consumes.