The Collaborative International Dictionary of English v.0.48:

Toxodon \Tox"o*don\, n. [Gr. to`xon a bow + ?, ?, a tooth.]
   (Paleon.)
   A gigantic extinct herbivorous mammal from South America,
   having teeth bent like a bow. It is the type of the order
   Toxodonta.
   [1913 Webster]