A new Miocene vertebrate fossil locality was found in Mae Soi, Chiang Mai Province. A nearly complete gomphothere skeleton was excavated from this site, together with several fragmental mammalian fossils. The gomphothere from Mae Soi could be either Archaeobelodon or gomphotherium. The age of deposits in which gomphothere skeleton occurred is provisionally dated as Early or Middle Miocene.

Partial skeletons of rhinocerotids were found in Na Sai, which is a well known locality of the Miocene in Northern Thailand. The rhinocerotid from this locality has been assigned to Gaindatherium, but cranial fragments included in a new skeleton suggest that the rhinocerotid from Na Sai could not be Gaindatherium but, rather, some other rhinocerotid is genus of Rhinocerotidae. Further analysis of the skeletal elements of this rhinocerotid is necessary.