Mecistotrachelos is an extinct genus of gliding reptile. The type and only known species is M. apeoros. This lizard-like animal was able to spread its ribs and glide on wing-like membranes. Mecistotrachelos had a much longer neck than other gliding reptiles of the Triassic such as Icarosaurus and Kuehneosaurus. It had unusual feet that may indicate its lifestyle as an arboreal insectivore. Two or three of the elongated ribs are very thick; though light bones are necessary for gliding, these thick bones may have supported muscles for more control in gliding.