\Lab`y*rin"tho*don\, n. [Gr. laby`rinqos labyrinth
+ 'odoy`s, 'odo`ntos, tooth.] (Paleon.)
A genus of very large fossil amphibians, of the Triassic
period, having bony plates on the under side of the body. It
is the type of the order Labyrinthodonta. Called also
{{Mastodonsaurus}}.