Abstract
The present investigation reports on the size and shape of teeth and the skull morphology of specimens from south-west Europe and North Africa genetically determined as Mus spretus and Mus musculus domesticus. The value of diagnostic characteristics and dental measurements classically used to distinguish the two species is tested. Revision is reported for 17 measurements and 14 morphological characters. Results were applied to unpublished fossil material from Morocco represented by lower molars. Late Pleistocene specimens of Mus from the fossil-bearing locality of Doukkala If near Rabat (Morocco) belong to a species that can be recognised as very close to M. spretus. This species likely settled in North Africa before the house mouse at a date that is still unknown.