APATORAPTOR

In 1993, an articulated skeleton was collected from the Horseshoe Canyon badlands near Drumheller, Alberta, sealed in a plaster field jacket, then set aside for almost a decade, because the specimen within was thought to belong to a common-as-muck ornithomimid. Preparators finally opened the jacket in 2002, but when they realised no skull was present, they promptly closed it again and returned it to storage. When the jacket was reopened in 2008, the content's true identity began to emerge: beneath the rock were clues that this animal wasn't an "ostrich mimic" at all, but a rare member of the caenagnathid family, a group of theropod dinosaurs related to oviraptorosaurids.

The lower jaw—completely toothless, like a bird's—had a shape unlike any known species and was attached to a long neck composed of at least eleven air-filled vertebrae with fused neck ribs. Just as distinctive were the back ribs, each sporting a slender, finger-like projection not seen in its close relatives. The shoulders and arms were robust, the ulna (one of two forearm bones) carried a row of small quill knobs—attachment points for strong, wing-like feathers, and its hands combined a short first metacarpal with an unusually long first finger. Taken together, those features confirmed that the specimen represented an entirely new critter: Apatoraptor pennatus—the feathered deceptive plunderer, despite initial suggestions that it represented the coeval caenagnathid Epichirostenotes curriei.