What features define Proconsul as an ape?

What features define Proconsul as an ape? How did Proconsul differ from living apes? What geological events of the Miocene influenced the evolution of the hominids? What were the most important changes in the landscape that affected hominid evolution? Most of the species making up the Miocene Hominid Radiation can be divided into those with thick molar enamel and with thin molar enamel. What are the probable relationships between these features and diet?