Final answer:
Australopithecines' diet was highly plant-based with moderate amounts of animal protein and fruits, while low in fats. Their diet varied based on the environment they lived in, with lush areas allowing for a greater variety of plants, and colder areas leading to more reliance on animal sources.
Step-by-step explanation:
The diet of Australopiths was extremely high in fibrous plant material, moderately rich in animal protein and fruits, and low in fats. These early hominids had a diet that consisted largely of edible plants such as nuts, fruits, berries, and wild grains, with a significant portion that came from animal sources, including fish, birds, insects, and land animals that were either scavenged or hunted. The robust form of Australopithecines, such as Paranthropus, had large grinding teeth for a coarse vegetarian diet, while the gracile form had smaller teeth indicative of a more varied diet including animal proteins.
In these diverse locales, depending on the available resources, the diet would adjust accordingly. A more plant-based diet was common in lush environments, whereas those in colder regions would have relied more on animal and fish resources. Regardless, as observed from the wear on their teeth and other anthropological research, the Australopiths consumed a wide range of foods, with human milk being the sole diet for infants. This lifestyle was characterized by high levels of dietary diversity and physical activity, shaping a diet that was not high in fat.