This animal, whose remains occur in the Lower Pliocene of both Attica and Samos, was about the size of a donkey, and possessed three pairs of upper incisor teeth, of which the innermost were large and trihedral, recalling those of the existing genus.
These are regarded as representing a distinct family, the Saghatheriidae, characterized by the possession of the full series of twenty-two teeth in the upper jaw, among which the first pair of incisors was modified to form trihedral rootless tusks, while the two remaining pairs were separated from one another and from the teeth in front by gaps.
The angle between two planes is termed dihedral, between three trihedral, between any number more than three polyhedral.
The cube may have originated by placing three equal squares at a common vertex, so as to form a trihedral angle.