 Subsequent digs in the same area during the 1930s unearthed 18 more specimens, and four specimens were found during the 1940s.Despite the large number of fossil specimens, the animal was not named or scientifically described during this time, though Barnum Brown of the AMNH gave it the informal name "Tenantosaurus", "sinew lizard", in reference to the extensive system of stiffening tendons in its back and tail.During the 1960s, Yale University began an extensive, long-term dig in the Big Horn Basin area (Cloverly Formation) of Montana and Wyoming.