羅伯特·巴克
Barnum Brown went on to collect several more tyrannosaurid specimens from Alberta, including the first to preserve the shortened, two-fingered forelimbs characteristic of the group (which Lawrence Lambe named "Gorgosaurus libratus", "balanced fierce lizard", in 1914). A second significant find attributed to "Gorgosaurus" was made in 1942, in the form of a well-preserved, though unusually small, complete skull. The specimen waited until after the end of World War II to be studied by Charles W. Gilmore, who named it "Gorgosaurus lancesnis". This skull was re-studied by Robert T. Bakker, Phil Currie, and Michael Williams in 1988, and assigned to the new genus "Nanotyrannus". It was also in 1946 that paleontologists from the Soviet Union began expeditions into Mongolia, and uncovered the first tyrannosaur remains from Asia. Evgeny Maleev described new Mongolian species of "Tyrannosaurus" and "Gorgosaurus" in 1955, and one new genus: "Tarbosaurus" ("terrifying lizard"). Subsequent studies, however, showed that all of Maleev's tyrannosaur species were actually one species of "Tarbosaurus" at different stages of growth. A second species of Mongolian tyrannosaurid was found later, described by Sergei Kurzanov in 1976, and given the name "Alioramus remotus" ("remote different branch"), though its status as a true tyrannosaurid and not a more primitive tyrannosaur is still controversial.