The ontogeny of the mandibular joint and the middle ear region was studied in Tupaiajavanica, Microcebus murinus, Nycticebus coucang and Tarsiusbancanus. During development, a passage connection was found between the mandibular condyle and Meckel’s cartilage that is produced by the primordium of the lateral pterygoid muscle. The articular disk is formed separately, and it appears later in development. A theory is presented on the interpretation of these finding