is a prefectural museum of natural history in Nagatoro, Saitama Prefecture, Japan. The museum opened in 1981 and replaced "å²" with "ã®" in its Japanese name in 2006. The Museum supersedes the (1949âÂÂ1980) and the (1921âÂÂ1949), founded by the Chichibu Railway Company. The collection includes 56 pieces from a Stegodon aurorae skeleton found in 1975, of which there are a further 3 pieces in the Sayama City Museum; both assemblages have been designated a Prefectural Natural Monument.