The name of a genus of primates of anthropoid form that lived in East Africa in the early Miocene period, between 16 and 20 million years ago. Proconsul may be the ancestor of all the great apes, from human beings to orangutans, or it may be a side branch close to the point of divergence.
Of three species first identified, Proconsul africanus had the shortest and broadest face, P. major had the longest and narrowest, and P. nyanzae was in between. There's apparently been some argument about reclassification, as there is now also a species P. heseloni, and a new genus erected for a very similar creature called Ugandapithecus major.
Proconsul africanus was discovered by Mary Leakey in 1947 and reported and named by Louis Leakey in 1948. (At least that's how I interpret slightly contradictory articles I've read on the Web.) The location was Rusinga Island, in the Kenyan waters of Lake Victoria. It was named after a famous performing chimpanzee at the Folies-Bergère.
In November 2004 scientists reported the discovery of another possible ancestor of great apes including humans, which they named Pierolapithecus catalaunicus, dating to about 13 million years ago. It is not yet clear how this would be related to the Proconsul genus.
Pictures of the skull of P. africanus at
http://ampere.scale.uiuc.edu/anth102/proconsul.html
http://www.toyen.uio.no/palmus/galleri/montre/english/x527.htm
Pierolapithecus update 2004: http://news.bbc.co.uk/2/hi/science/nature/4014351.stm