User:Ndayap/Australopithecus anamensis

Physical Characteristics
Based on fossil evidence, A. anamensis expresses high degrees of sexual dimorphism. Although considered to be the more primitive of the australopiths, A. anamensis had parts of the knee, tibia, and elbow that were different from apes, which indicates bipedalism as the species' form of locomotion. Specifically, the tibia bone of A. anamensis has a more expansive upper end with bone.

In addition to the modified body parts that indicate bipedalism, A. anamensis fossils show evidence of tree climbing. Archeology finds indicate that A. anamensis had long forearms, as well as modified features of the wrist bone. Both the forearms and finger bones of A. anamensis indicate a potential of utilizing the upper limbs as support when operating in trees or on the ground. Forearm bones belonging to A. anamensis have been found to be 265 millimeters to 277 millimeters in length. The curved proximal hand phalanx of A. anamensis in the fossil record that contains strong ridges is indicative of its potential ability to climb.

Fossil evidence reveals that A. anamensis had a somewhat wide jaw joint that was flat from front to back, which resembles a curvature similar to those seen in great apes. Furthermore, the ear canal of A. anamensis fossils are narrow in diameter. The ear canal most resembles that of chimpanzees and is contrasting to the wide ear canals of both later Australopithecus and Homo.

The first lower premolar of A. anamensis is characterized by a singular large cusp. Additionally, A. anamensis has a narrow first milk molar that contains a large dominant cusp with minimum surface area, which may have been used for crushing.