simplicidentata

from The Century Dictionary.

• noun The simple-toothed rodents, or simplicident Rodentia, a suborder containing all living rodents except the Duplicidentata, having only one pair of upper incisors, or the Myomorpha, Sciuromorpha, and Hystricomorpha, as rats and mice of all kinds, squirrels, beavers and their allies, and porcupines and their allies. See Duplicidentali. Also called Simplicidentati when the order is named Glires instead of Rodentia.