Tanius (meaning "of Tan") is a genus of hadrosauroid dinosaur. It lived in the Late Cretaceous of China. The type species, named and described in 1929 by Carl Wiman, is Tanius sinensis. The generic name honours the Chinese paleontologist Tan Xichou ("H.C. Tan"). The specific name refers to China. In 2010 Gregory S. Paul estimated the length of Tanius at seven metres and the weight at two tonnes. Exact cladistic analyses resulted in Tanius being placed either basal in the Hadrosauroidea, basal in the Hadrosauridae, also dependent on the definition of the latter concept, or in the Hadrosaurinae