Final answer:
Louis and Mary Leakey were the renowned paleoanthropologists who first identified Homo habilis in 1960. They contributed to establishing classification criteria for the genus Homo that include brain size, skull shape, tool usage, and other physiological features.
Step-by-step explanation:
The species known as Homo habilis was first discovered and identified by the famous team of paleoanthropologists Louis and Mary Leakey in 1960. This discovery was groundbreaking in the field of human evolution studies. Other notable anthropologists such as Donald Johanson are known for different discoveries, such as the famous Lucy skeleton, but it was indeed the Leakeys who discovered Homo habilis.
Criteria used to classify a species under the genus Homo, apart from bipedalism, include a brain size over 600 cc, a round and globular skull, use of tools, reduced prognathism, smaller jaws and mandibles, humanlike postcranial features, and feet fully adapted for walking. The Leakeys, along with John Napier and primatologist Phillip Tobias, provided extensive research on Homo habilis, establishing it as one of the earliest known species in the genus Homo.