A giant termite of the genus <i>Gyatermes</i> from the late Miocene of Nagano Prefecture, Japan (Isoptera)

A new species of the termite genus Gyatermes Engel &amp; Gross (Archotermopsidae) is described and figured from a beautifully preserved forewing in late Neogene sediments of Nagano Prefecture, central Japan.  The approximately 27-mm long forewing of Gyatermes naganoensis Engel &amp; Tanaka, new species, is preserved in Late Miocene (late Messinian) mudstone of the Ogawa Formation ( ca . 6 Ma), and is distinguished from its slightly older and larger congener G. styriensis Engel &amp; Gross, from the early Tortonian of Styria, Austria.  Comments are provided regarding the paleoclimatic implications of a giant termite in the Miocene fauna of Nagano.