Final answer:
The three minor Pliocene hominins of the genus Australopithecus are Australopithecus bahrelghazali, Australopithecus garhi, and Australopithecus sediba. These species were part of the gracile australopiths and are less well-known compared to their relatives like Australopithecus afarensis and Australopithecus africanus.
Step-by-step explanation:
Minor Pliocene Hominins of the Australopithecus Genus
The three minor Pliocene hominins apart of the genus Australopithecus are Australopithecus bahrelghazali, Australopithecus garhi, and Australopithecus sediba. These species are considered lesser-known or minor because they are not as well represented in the fossil record as some of their relatives, such as Australopithecus afarensis and Australopithecus africanus. Australopithecus bahrelghazali and Australopithecus garhi emerged around 4 million years ago (MYA) and disappeared by 2 MYA. The gracile species, including these minor australopiths, had a slender build relative to the robust australopiths of the genus Paranthropus, which includes Paranthropus robustus, P. boisei, and P. aethiopicus. The robust species persisted for about another million years beyond the gracile forms.
The gracile australopiths, including the minor species in question, are of particular interest in the study of human evolution for their bipedal locomotion and evolutionary relationship to the genus Homo. As minor species, Australopithecus bahrelghazali is notable for being the only australopith found in Central Africa, while the position of Australopithecus sediba is particularly significant due to some features it shares with the Homo genus, indicating a possible evolutionary link.