Saurornitholestes langstoni (Langston's lizard-bird thief) is a coyote-sized carnivorous dromaeosaurid dinosaur genus from the Upper Cretaceous (Upper Campanian) of Alberta, Canada. Several incomplete skeletons, dozens of isolated bones, and scores of teeth are known from the badlands of Dinosaur Provincial Park in Alberta; most of these are housed at the Royal Tyrrell Museum of Palaeontology, in Drumheller, Alberta.
Like other theropods in the family Dromaeosauridae, Saurornitholestes had a extended, curving, bladelike claw on the second toe. Saurornitholestes was more long-legged and flippantly built than other dromaeosaurids such as Velociraptor and Dromaeosaurus. It resembles Velociraptor in having large, fanglike teeth in the face of the jaws. Saurornitholestes most intimately resembles Velociraptor, although the precise relationships of the Dromaeosauridae are still comparatively poorly understood.
Saurornitholestes appears to have been the most ordinary small theropod in dinosaur Provincial Park and teeth and bones are much more ordinary than those of its more massive contemporary, Dromaeosaurus. Little is known about what it ate and how it lived, but a tooth of Saurornitholestes has been found entrenched in the wing bone of the pterosaur Quetzalcoatlus. Whether it in fact killed the pterosaur or merely scavenged an already dead animal is unknown.
Similar teeth are established in younger deposits, but whether they stand for S. langstoni or a different, related species is unknown.