Final answer:
The first taxa with distinctive primate features appeared about 55 MYA in the Eocene epoch, resembling modern-day prosimians like lemurs. The earliest fossil records of true anthropoid primates are found in the Oligocene epoch primates from the Fayum site. The Order Primates is divided into Strepsirrhini (prosimians) and Haplorrhini (tarsiers, simians, humans), highlighting the evolution of distinctive traits throughout primate history.
Step-by-step explanation:
First Taxa with Distinctive Primate Features
The first taxa with distinctive primate features can be traced back to the Eocene epoch, approximately 55 million years ago (MYA). The emergence of true primates during this period marked the beginning of the lineage leading to modern prosimians and anthropoids. The prosimians bear a resemblance to today's lemurs, with primate characteristics such as pentadactyl limbs (five fingers) and various types of teeth adapted for diverse diets. In contrast, anthropoids, including monkeys, apes, and humans, have evolved larger brains and different facial structures, compared to prosimians.
Notable among the early primates are the Oligocene epoch fossils, such as those from the Fayum site, which include Parapithecoidea and Propliopithecoidea. With characteristics like a third premolar and a dental formula associated with catarrhine primates, the propliopithecoideans are believed to be among the earliest Old World monkeys. Similarly, based on dental formula traits, it is suggested that Propliopithecus may represent the earliest New World monkeys.
The Order Primates is broadly divided into Strepsirrhini (including prosimians like lemurs) and Haplorrhini (encompassing tarsiers, simians, and humans). While prosimians tend to be nocturnal with smaller brains, the haplorrhines have developed more reliance on vision and are generally diurnal, with the notable exception of tarsiers. This division underscores the evolutionary divergence and development of distinctive primate features that have led to the diverse Order of Primates that we observe today, including our own species, Homo sapiens.