 In 1948 he was a member of the Joint Soviet-Mongolian Paleontological Expedition conducted on the Gobi Desert of Mongolia.The expedition ended up on the discovery of "Talarurus", and later described by him in 1952.When first described, based on the claws, Maleev interpreted the remains of "Therizinosaurus" as belonging to a gigantic turtle-like reptile, also he named the family Therizinosauridae.