Labyrinthodon \Lab`y*rin"tho*don\, n. [Gr. laby`rinthos
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}.
[1913 Webster]