Final answer:
Obligate bipedalism means an animal exclusively uses two-legged walking as its mode of locomotion, supported by specific anatomical adaptations.
Step-by-step explanation:
Obligate bipedalism means that an animal's method of locomotion is exclusively walking on two legs. This form of locomotion is a defining characteristic of modern humans, as well as an attribute of some extinct hominins and certain types of dinosaurs. Anatomical adaptations such as the angling of the femur at a valgus angle, evolutionary changes in the spinal curves, the development of foot arches, and the alignment of the toes support bipedal stance and movement. These changes allow for balance on one leg, the stance leg, while the other leg, the step leg, is moving forward. Specifically, bipedal animals have evolved to have their knees and feet positioned under the center of the pelvis for better weight distribution during locomotion.