Qaidam Basin
So far, there are two known species, "T. hedini", and the recently described "T. brevirostrum". The scrappy remains of the first species, "T. hedini", were discovered by Dr Hedin at the Qaidam Basin during the Sino-Swedish Scientific Expedition to Northwest China during the 1930s. Partial remains of two individuals were discovered in the Liushu Formation within the Linxia Basin in Hezheng County, Gansu, in 2004, and were described as "T. brevirostrum" in 2013.