the latter being a younger animal, and distinct from Tyrannosaurus recognized by A.K. Rozhdestvensky who recombined the species as Tarbosaurus bataar. In the 1970s saw the description of two genera. In 1970 saw the publication of Daspletosaurus, with the holotype CMN 8506 consisting of a partial skeleton including the skull, the shoulder, a forelimb, the pelvis, a femur and all of the vertebrae from the neck, torso and hip, as well as the first eleven tail vertebrae. It was discovered in 1921 near Steveville, Alberta, by Charles Mortram Sternberg, who thought it was a new species of Gorgosaurus, but was found to be a new genus by Dale Russell using the aforementioned CMN 8506. The second, Alioramus, described in 1976 by Sergei Kurzanov which the holotype (PIN 3141/1) is a partial skull associated with three metatarsals found by a joint Soviet-Mongolian expedition to the Gobi Desert in the early 1970s found these remains at a locality known as Nogon-Tsav in the Mongolian province of Bayankhongor, Nemegt Formation. From 1977 to 2009 saw the publications of several genera. In Asia they include Shanshanosaurus (1977), Maleevosaurus (1992), and Raptorex (2009), while in North America saw Nanotyrannus (1988), Dinotyrannus and Stygivenator (1995). These genera, however are controversial as the remains of these animals are immature or juvenile individuals. As of 2021 it is widely understood that the Asian specimens are early growth stages of Tarbosaurus, while the North American specimens are those of Tyrannosaurus. Valid genera would not be named until the 2010s, where in 2011 announced the publication of Teratophoneus by Thomas D. Carr and colleagues. The fossils were first found in the Kaiparowits Formation of southern Utah. Later, fossils from the same formation were discovered and identified as the genus. Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous period. This date means that Teratophoneus lived in the middle of the Campanian stage of the Late Cretaceous. In the same year Zhuchengtyrannus was named by David W. E. Hone and colleagues based on the holotype ZCDM V0031, a nearly complete right maxilla and associated left dentary (lower jaw, both with teeth) housed at Zhucheng Dinosaur Museum. In 2014 came Nanuqsaurus, the northern most tyrannosaurid found in Prince Creek Formation of the North Slope of Alaska, United States. In the same year also announced Qianzhousaurus known