The age of the recently created hominoid species from Thailand, cf. Lufengpithecus chiangmuanensis Chaimanee et al., 2003  , was originally estimated to be ca 13–13.5 Ma, based on faunal and palaeomagnetic correlations. Previous studies of the Chiang Muan fauna (including hominoids) and palaeomagnetism suggest that the deposits are appreciably younger than this, being closer in age to Xiaolongtan (China) (ca 12–11 Ma) rather than to the Chinji fauna of Pakistan. The similarities between hominoids from the Thai and Chinese localities are clear, and we conclude that cf. L. chiangmuanensis should be treated as a synonym of ?Lufengpithecus keiyuanensis Wu, 1957.
PICKFORD M., NAKAYA H., KUNIMATSU Y., SAEGUSA H., FUKUCHI A. & RATANASTHIEN B. 2004. — Age and taxonomic status of the Chiang Muan (Thailand) hominoids. Comptes Rendus Palevol 3 (1): 65-75. https://doi.org/10.1016/j.crpv.2003.09.029