Final answer:
Paleocene pro-primates like Purgatorius had basic primate features, while Eocene eu-primates shared more with modern primates, including fully bony postorbital bars. Carpolestes shows transitional features between these groups. Miocene apes' adaptations allowed for greater ecological and geographical range.
Step-by-step explanation:
The Paleocene pro-primates, represented by creatures like Purgatorius, show primitive primate characteristics like elongated molars and enlarged central incisors. In contrast, Eocene eu-primates have more features in common with modern primates, such as fully bony postorbital bars and specialized teeth structures like a toothcomb. Ankle bones of Eocene primates were also complex, which is believed to have contributed to their success in different environments.
These differences are relevant to three hypotheses explaining primate emergence: the arboreal hypothesis, which suggests that primates evolved traits for life in the trees; the visual predation hypothesis, indicating that enhanced vision and grasping were important for predation; and the angiosperm radiation hypothesis, which ties primate evolution to the spread of flowering plants.
Carpolestes, a possible transitional species, exhibited characteristics suggesting it was an intermediate form. It had primate-like grasping hands and feet but also showed non-primate dental characteristics, bridging the gap between primitive proprimates and more advanced eu-primates.
Miocene apes, such as Proconsul, lacked certain arboreal adaptations seen in modern apes, like long curved digits; however, they had adaptations like lack of a tail and specific teeth patterns, which allowed them to exploit a variety of niches and spread geographically further than predecessors. Sivapithecus, with its thick dental enamel, also suggests a diet that allowed these apes to thrive in diverse environments.