<P> The island is also notable as the family home and burial site of Tom Mboya, who before his assassination in 1969 was widely pegged as Jomo Kenyatta's successor as President of the new nation of Kenya . </P> <P> Rusinga is widely known for its extraordinarily rich and important fossil beds of extinct Miocene mammals, dated to 18 million years . The island had been only cursorily explored until the Leakey expedition of 1947 - 1948 began systematic searches and excavations, which have continued sporadically since then . The end of 1948 saw the collection of about 15,000 fossils from the Miocene, including 64 primates called by Louis Leakey "Miocene apes ." </P> <P> All the species of Proconsul were among the 64 and all were given the name africanus, although many were reclassified into nyanzae, major and heseloni later . Mary Leakey discovered the first complete skull of Proconsul, then considered a "stem hominoid", in 1948 . Excavation of the fossil was completed by Louis' native assistant, Heselon Mukiri (whence Walker's 1993 name heseloni). Many thousands of fossils are now known from five major sites, with abundant hominoids including an almost complete skeleton of a second species of Proconsul, as well as Nyanzapithecus, Limnopithecus, Dendropithecus and Micropithecus, all of which show arboreal rather than terrestrial adaptations . The first true monkeys do not appear until around 15 million years ago, so it is widely supposed that the diverse Early Miocene African catarrhines like those found on Rusinga filled that adaptive niche . The phylogenetic position of these primates has been debated . It has been theorized that Proconsul is a stem catarrhine and therefore ancestral to both Cercopithecids (Old World monkeys) and hominids (great apes and humans), rather than a stem hominoid . </P> <P> Pleistocene mammal fossils, including an extinct antelope called Rusingoryx, notable for its nasal dome hypothesised to produce loud calls, known nowhere else, are also common in former shoreline deposits around the edges of the island, left behind as Lake Victoria has slowly subsided over the centuries due to erosion in its outlet . </P>

Who discovered the first skull of a fossil ape on rusinga island