Here's a breakdown:
* Australopithecines: These are the most well-known primates from the Pliocene. They were bipedal (walked on two legs) and possessed a mix of ape-like and human-like features. Famous examples include:
* Australopithecus afarensis (Lucy): Lived 3.9 to 2.9 million years ago in East Africa. Lucy's skeleton, discovered in 1974, is one of the most complete hominin fossils ever found.
* Australopithecus africanus: Lived about 3 to 2 million years ago in South Africa.
* Paranthropus: A group of robust australopithecines with large teeth and powerful jaws, adapted for chewing tough vegetation.
Other Pliocene Primates:
* Ardipithecus: These species, like *Ardipithecus ramidus*, lived about 4.4 million years ago and showed a combination of tree-climbing and ground-dwelling adaptations.
* Kenyanthropus: These hominins, like *Kenyanthropus platyops*, lived about 3.5 million years ago and had a flat face, suggesting a possible shift in diet.
What Makes Them Human-like?
* Bipedalism: Walking upright on two legs was a key adaptation for moving around on the African savanna and freeing the hands for tool use.
* Brain Size: While still smaller than modern human brains, their brain size was larger than other apes, indicating some cognitive abilities.
* Tool Use: Some evidence suggests rudimentary tool use in some australopithecines.
Important to Note:
* This is a complex and ever-evolving field of study. New discoveries constantly challenge existing hypotheses about human evolution.
* There were likely many other hominin species that existed during the Pliocene. We may not even know about them yet, as the fossil record is incomplete.
If you have more specific questions about any of these species, feel free to ask!