Paleocene primates : very different from present-day conditions, hotter, more humid, we think first primates show up. Recent: plesiadapids not primates: no postorbital bar, claws instead of nails, eyes placed on side of head, enlarged incisors. Omomyid (shoshonius) and what we think they looked like. Warning: similarity in form does not always equate with close phylogenetic relationships www. notesolution. com. Three (3) haplorhine features: fused frontal bone, full postorbital closure, fused mandibular symphasis. South american primates: primates appear for first time in fossil record of south america towards late. Oligocene: origins of south american primate unclear, may have rafted over from africa. Early (23. 0-16. 0 mya) monkeys & apes (e. g. proconsul) apparently confined to africa. Middle (16. 0-11. 6 mya) ape-like catarrhines (e. g. dryopithecus) widesparead and diverse in. Late (11. 6-5. 3 mya) apes (e. g. sivapithecus) became rarer as woodlands and forests replaced by drier and more open habitats.