Pronunciation: ah-TROSS-ih-RAP-tor
Meaning: Savage Plunderer
Author/s: Currie and Varricchio (2004)
Synonyms: None known
First Discovery: Alberta, Canada
Discovery Chart Position: #534
Atrociraptor marshalli
Known only from a skull made up of parts of the upper and lower jaws, bone fragments and teeth, dragged from Alberta's Horseshoe Canyon Formation, Atrociraptor was likely every bit as savage as the name implies.
It possessed a proportionately shorter and deeper snout than its dromaeosaur relatives, suggesting greater bite power. And its teeth, of different sizes but uniformly blade-like and generously serrated, were only modestly curved but emerged from their sockets angled backwards. Those features combined are perfect for snagging live prey and tearing flesh from its bones, yet they were attached to a critter no more than a couple of meters long and 15 kg in weight.
Currie and Varricchio's 2004 analysis placed Atrociraptor closest to Deinonychus and Bambiraptor, grouping all three within Velociraptorinae, a dromaeosaurid subfamily anchored by Velociraptor. In 2009, Longrich and Currie recovered Atrociraptor as closer to Bambiraptor and Saurornitholestes and moved the trio to their own dromaeosaurid subfamily that they dubbed Saurornitholestinae.
Among dromaeosaurids, the upper jaw of Atrociraptor is unique in having one opening (the maxillary fenestra) directly above another (the promaxillary fenestra) rather than well behind it.
It possessed a proportionately shorter and deeper snout than its dromaeosaur relatives, suggesting greater bite power. And its teeth, of different sizes but uniformly blade-like and generously serrated, were only modestly curved but emerged from their sockets angled backwards. Those features combined are perfect for snagging live prey and tearing flesh from its bones, yet they were attached to a critter no more than a couple of meters long and 15 kg in weight.
Currie and Varricchio's 2004 analysis placed Atrociraptor closest to Deinonychus and Bambiraptor, grouping all three within Velociraptorinae, a dromaeosaurid subfamily anchored by Velociraptor. In 2009, Longrich and Currie recovered Atrociraptor as closer to Bambiraptor and Saurornitholestes and moved the trio to their own dromaeosaurid subfamily that they dubbed Saurornitholestinae.
Among dromaeosaurids, the upper jaw of Atrociraptor is unique in having one opening (the maxillary fenestra) directly above another (the promaxillary fenestra) rather than well behind it.
Etymology
Atrociraptor is derived from the Latin "atrox" (savage) and "raptor" (plunderer or snatcher).
The species epithet, marshalli, honours Wayne Marshall of East Coulee, Alberta, Canada, who discovered the type specimen.
Discovery
The first fossils of Atrociraptor were discovered 5 metres above the Daly Coal seam in the Horseshoe Canyon Formation at Drumheller, Alberta, Canada, about 5 km west of the Royal Tyrell Museum where they are now housed, by Wayne Marshall in 1995.
The holotype (TMP 95.166.1) is a partial skull.
