 Woodward (1888) notes that "In 1881, a tail, completely sheathed in bony armour like that of "Glyptodon," was found at the same spot in King's Creek whence had been obtained [the "Ninjemys" holotype skull]".Gafney (1992) notes that this consists of a "tail club and single tail ring", this is assumed to belong to the holotype individual.In 1992, anatomical differences with the type species "M. platyceps" led to its placement in the new genus "Ninjemys", which was named in honor of the Teenage Mutant Ninja Turtles.