''Aztlanolagus'' may be distinguished from all other known leporids as follows. Lower incisor terminates under diastema and well anterior to P₃. Three reentrant folds present on trigonid of P₃: an anterior reentrant fold, an anterointernal reentrant fold (rarely cut off to form an enamel lake), and an anteroexternal fold. At all growth stages, a posteroexternal reentrant fold extends approximately halfway across occlusal surface of P₃ to a narrow enamel lake lying next to lingual border; enamel lake rarely joined to external reentrant to form the ''Lepus''-type pattern (Hibbard, 1963). On P₄ to M₂, external fold extends to enamel of lingual wall. Anterior border of talonid on P₄-M₂ deeply convoluted, often with alternating series of major and minor enamel loops.... (Russell and Harris 1986:632-633)