By Maina Kiarie
Proconsul is an extinct genus of primates that existed from 23 to 5 million years ago. Fossil remains are present in Eastern Africa including Kenya and Uganda and one excellent fossil can be viewed at the Nairobi Museum. Four species of the Proconsul genus have been classified to date: P. africanus, P. heseloni, P. major and P. nyanzae. The four species differ mainly in body size. The environment Proconsul lived in during the Early Miocene (between 23.03 million and 5.33 million years ago) ranged from forested environments to more open, arid grasslands.
While a prospector was digging about for gold in Koru, near Kisumu in Western Kenya in 1909, he discovered a partial primate jaw. The name Proconsul was devised by Arthur Hopwood in 1933 and means “before Consul”. At the time, captured chimpanzees used for performances in circuses were at the time named Consul. In 1894, when a chimpanzee at the Belle Vue (not the Belle Vue estate in Nairobi) Zoo in Manchester, England, died, a poet called Ben Brierley, wrote a commemorative poem wondering where the “Missing Link” between chimpanzees and men was.
Arthur Hopwood had in 1931 discovered the fossil of three individuals in the vicinity of Lake Victoria in an expedition with Louis Leakey. He named the fossils after a popular chimp located in the London Zoo at the time. Hopwood named the fossil by adding ‘Pro’ to ‘Consul’, meaning “ancestral to the Chimpanzee.” He also added ‘africanus’ as the species name.
For many decades later, Proconsul was the oldest fossil hominoid known until recently. It was also the first fossil mammal ever found in sub-Saharan Africa. Hominoid or hominin or hominid means a primate belonging to a group that includes humans, human fossil ancestors and other great apes like gorillas and orangutans)
Mary Leakey found another fossil in 1948 as did Thomas Whitworth in 1951. These fossils found in Koru and Songhor in western Kenya were classified as Proconsul heseloni by Alan Walker in 1993, though are still considered by others to be Proconsul africanus.
Louis Leakey was the first to propose the family of Proconsulidae in 1962. Eleven years earlier, together with Wilfrid Le Gros Clark, he had defined africanus, nyanzae and major.
Classifying hominoids in the second half of the 20th Century has been fraught with complexity, disagreement and controversy. Most palaeoanthropoligists change their minds as new fossils are unearthed and new observations made. This is to be expected of the scientific method. The classification found in books published in the previous decades have changed and differed.