Paranthropus robustus was an early hominin species that lived in South Africa approximately two million years ago, coexisting with early Homo—a group that led directly to modern humans. Abundant skull and dental fossils have revealed much about the diet and social organization of Paranthropus robustus. However, the rarity of finding well-preserved, taxonomically diagnostic postcranial elements in the South African fossil record has complicated interpretations of its biology. Recently, an articulating leg, including hipbone, thigh bone, and shin bone from Swartkrans Member 1 (M1) has been attributed to Paranthropusrobustus based on the external morphology of the proximal femur, offering, for the first time, deeper insights into the species’ body size, stature, posture, and locomotion.