The type specimen, or holotype, of Latenivenatrix (CMN 12340) was originally described in 1969 by Dale Alan Russell and referred by him to the genus Stenonychosaurus. In 1987, it was referred to the now dubious genus Troodon. It was collected in 1968 by Irene Vanderloh in the Dinosaur Park Formation strata from Alberta, Canada. The specimen has preserved some skull bones, such as the frontals, parietals, postorbital, basioccipital, and basisphenoid, four vertebrae, four ribs, some chevrons, gastralia, a fairly complete arm, and incomplete legs.
