M

Middle Miocene site on the island of this name in the Winam Gulf of western Kenya. Fossil-bearing clays and silts beneath phonolite lava on the island, and on the nearby mainland at Majiwa Bluff and Kaloma, were first excavated by the British missionary W.E. Owen in the early 1930s. More than 1,000 primate specimens have been found, mostly by sieving the material in Owen's dumps and in recent excavations directed by B. Benefit and M. McCrossin. Twenty beds of sediment and tuff have been defined, with the majority of specimens coming from Beds 3 and 5 (counting up from the base of the section). Bed 8 is dated ca. 14.7 Ma and Bed 20 ca. 13.8 Ma, according to ³⁵Ar/⁴⁰Ar laser-fusion dates, in confirmation of previous faunally based estimates of 15 Ma for the primary fauna.