Final answer:
Cercopithecoids, hominoids, and hominins are all primate groups under the suborder Haplorrhini. Cercopithecoids are Old World monkeys with distinct molars, while hominoids are tailless, terrestrial apes and humans. Hominins are directly related to modern humans and unique for their bipedality.
Step-by-step explanation:
Cercopithecoids, Hominoids, and Hominins
Cercopithecoids, colloquially known as Old World monkeys, hominoids which include apes, and hominins which cover the human lineage, are all members of the suborder Haplorrhini, notable primates that share several characteristics but also showcase evolutionary differences. The Haplorrhini or Anthropoids like tarsiers, New World monkeys, Old World monkeys, apes, and humans are distinctive due to their dry noses and forward-facing eyes. Within the suborder, hominoids and hominins have a closer evolutionary relationship with humans.The most distinctive feature of the cercopithecoids is their molars with two parallel ridges. Examples include baboons, mandrills, and macaques. Hominoids which include the tailless gibbons, orangutans, chimpanzees, gorillas, and humans are largely terrestrial. Our direct ancestors, the hominins, are unique for their bipedal locomotion and include genera such as Homo, Australopithecus, and Paranthropus. These varying primate groups represent the complexity and diversity of primate evolution, leading to the existence of modern humans.