The Laetoli footprint trail indicates what about the foot of Australopithecus?

• A. It had a non-divergent big toe and an arch similar to modern humans.
• B. It had a fully opposable big toe like modern chimpanzees.
• C. It lacked any evidence of bipedal locomotion.
• D. It was adapted for swimming rather than walking.

Answer: (A)

Verified step by step guidance

1. Understand the context: The Laetoli footprints are fossilized footprints discovered in Tanzania, dating back approximately 3.6 million years. They are attributed to Australopithecus afarensis and provide evidence of locomotion and foot structure.
2. Analyze the options: The question asks about the foot structure of Australopithecus based on the Laetoli footprints. Consider the anatomical features of the footprints, such as the presence of an arch and the alignment of the big toe.
3. Recall key concepts: Modern humans have a non-divergent big toe and an arch in the foot, which are adaptations for bipedal locomotion. In contrast, chimpanzees have a fully opposable big toe for grasping, and swimming adaptations are unrelated to terrestrial footprints.
4. Evaluate the evidence: The Laetoli footprints show a non-divergent big toe and an arch, indicating bipedal locomotion similar to modern humans. This rules out options suggesting opposable big toes, lack of bipedalism, or swimming adaptations.
5. Select the correct answer: Based on the anatomical evidence from the footprints, the correct interpretation is that Australopithecus had a non-divergent big toe and an arch similar to modern humans, supporting bipedal locomotion.