Skull and lower jaw of Late Cretaceous (?middle Campanian) eutherian zalambdalestid genus Barunlestes from the Gobi Desert in Mongolia is described and figured. It is characterized by: maxilla extending backwards along the

choanae, the presphenoid with a prominent median process, very large pterygoid process of basisphenoid, a fissura Glaseri, postglenoid process extending only opposite the medial part of glenoid fossa, large promontorium, foramen arteriae stapediae, sulcus arteriae stapediae, no sulcus arteriae promontorii. Large promontoria and large olfactory bulbs indicate strong development of auditory and olfactory senses in Barunlestes. Basicranial structure of Barunlestes supports Presley's (1979) idea that the primitive mammalian morphotype with two vessels (medial internal carotid and promontory), should be revised.