The intestine (except in the dormice or Gliridae) has a large caecum.
In the dormice, forming the section Myoxidea, with the single family Gliridae (or Myoxidae), a single pair of premolars may or may not be present; the molars are short-crowned and rooted, with transverse From de Winton.
The beavers (Castoridae) are restricted to the northern hemisphere, whereas the dormice (Gliridae) and the mole-rats (Spalacidae) are exclusively Old World forms, the latter only entering the north of Africa, in which continent the former are largely developed.
This rodent, Muscardinus avellanarius, is the sole representative of its genus, but belongs to a family - the Gliridae, or Myoxidae - containing a small number of Old World species.
