Final answer:
The five species of australopithecines share characteristics such as distinct facial prognathism in gracile types, robust types with pronounced sagittal crests for strong jaw muscles, and evidence of bipedalism in the pelvic structure and foramen magnum positioning.
Step-by-step explanation:
Three characteristics of the five species of australopithecines can be summarized by looking at their morphology, specifically focusing on cranial features, dental structures, and locomotion abilities. Firstly, gracile australopithecines, such as Australopithecus afarensis and Australopithecus africanus, exhibited more pronounced facial projection (prognathism), smaller teeth and jaws, and a lack of a sagittal crest. Secondly, robust australopithecines exhibited a prominent sagittal crest to accommodate larger jaw muscles, indicating adaptation to a diet of tough plant materials. Lastly, all australopithecines, both robust and gracile, exhibited evidence of bipedalism, such as changes in the shape of the pelvis and positioning of the foramen magnum closer to the center of the base of the skull, although their locomotion also included arboreal activities indicated by their long and curved fingers and toes.