Simplicidentata
... that Simplicidentata, the group including rodents and their closest extinct relatives, is characterized by the loss of a pair of upper incisors?
... that <b id="mwFME"><a href="./Simplicidentata" id="mwFMI" rel="mw:WikiLink" title="Simplicidentata">Simplicidentata</a></b>, the group including <a href="./Rodent" id="mwFMM" rel="mw:WikiLink" title="Rodent">rodents</a> and their closest extinct relatives, is characterized by the loss of a pair of upper <a href="./Incisor" id="mwFMQ" rel="mw:WikiLink" title="Incisor">incisors</a>?