Hexing is an extinct genus of basal ornithomimosaur dinosaur known from the Early Cretaceous of northeastern China. It contains a single species, Hexing qingyi.
In the early twenty-first century, a local farmer at Xiaobeigou in Liaoning discovered the skeleton of a small theropod. He prepared the fossil himself, trying to enhance its value by restoring damaged bones and adding fake parts. Eventually the specimen was obtained by the Geological Museum of Jilin University and more expertly prepared, during which process the added parts were again removed.[1]
In 2012, the type species Hexing qingyi was named and described by Jin Liyong, Chen Jun and Pascal Godefroit. The generic name means "like a crane" in Chinese. The specific name means "with slender wings".[1]
The holotype, JLUM-JZ07b1, was found in fluvial deposits of the lower Yixian Formation, which have a highest possible age of 139 million years and a lowest of 128 million years and thus date from some time in the early Valanginian to early Barremian stage. It consists of a partial skeleton, containing the skull, the lower jaws, a series of five cervical vertebrae, the shoulder girdle and the majority of both forelimbs and hindlimbs. The remains have not been well preserved. The specimen represents a subadult or adult individual.[1]
The holotype specimen consists of the remains of a small individual. Because most of the vertebral column is absent, its body length cannot be directly determined, but a comparison can be made with the previously smallest known ornithomimosaur, the 1.6 metres long Shenzhousaurus, which has a thighbone length of 191 millimetres, while the femur length of Hexing is 135 millimetres. Such a small body size was among ornithomimosaurs up till now only known from juveniles but the holotype is not a young animal as is shown by the complete fusion of the skull bones, the neck ribs, the scapulocoracoid and the ankle bones.[1]
The describers determined some autapomorphies of Hexing, its unique derived traits. The snout tip reaches downwards in front of the lower jaws, so deeply that the roof of the mouth at this point is at a level with the bottom edge of the lower jaw. The fossa antorbitalis, a depression on the side of the maxilla, covers almost the entire outer surface of that bone. The parietal bones are joint at their midline in a crest. The large bone extensions at the back of the skull, the processus paroccipitales, are hanging down below the level of the foramen magnum. In the lower jaw, the dentary has an opening in its side. The formula for the phalanges of the hand is 1-2-3-0-0 or 2-3-3-0-0 — or 0-1-2-3-0/0-2-2-3-0 if the three fingers of the hand are interpreted as the second, third and fourth. The upper phalanges of the second and third (or third and fourth) finger are elongated with more than 75% of the length of the corresponding metacarpal. The lower leg is relatively long with the tibiotarsus having 137% of the length of the thighbone.[1]