Aachenosaurus is a dubious genus of prehistoric plant. It was named based solely on fossilized fragments of material that were originally thought to be jaw fragments from a duck-billed dinosaur (a hadrosaur). However, the fossils turned out to be petrified wood, to the great embarrassment of the discoverer. The fossil's name means "Aachen lizard", named for the Aachenian deposits of Moresnet (which was a neutral territory between Belgium and Germany), where the fossils were found.
A synonym of Aachenosaurus is Aachenoxylon, which was coined by Dr Maurice Hovelacque in 1889/1890.