Genus: Machairasaurus LONGRICH, CURRIE & DONG, 2010
Etymology: Greek, machaira, "a forward-curving sword" (referring to the shape of the unguals), and Greek, sauros, "lizard";

Species: leptonychus LONGRICH, CURRIE & DONG, 2010
Etymology: Greek, leptos, "slender" and Greek, onychos, "claw."

Holotype: IVPP V15979

Locality: Bayan Mandahu, Urad Houqi, Inner Mongolia (Nei Mongolia), China.

Horizon: Bayan Mandahu Formation.

Biostratigraphy:

Age: Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: A partial skeleton including a nearly complete articulated right forearm and manus, fragments of the left manus and pedal phalanges.

Referred material:

IVPP V15980: A partial skeleton including manual and pedal phalanges, fragments of left metatarsals III and IV, caudal vertebrae, dorsal ribs and chevrons.