A. afarensis had a slender build, resembling a juvenile African Australopithecus (Australopithecus africanus). A. afarensis is thought to be more closely related to the genus Homo (which includes the modern human species, Homo sapiens), being either its direct ancestor or a close relative of an unknown ancestor. Some researchers include A. afarensis in the genus Praeanthropus. There is no photo of the Afar Australopithecus, but those who want to understand what this animal looked like can admire the unique illustrations and models that reconstruct the appearance of this primate. Modern technology works wonders, thanks to which the appearance of Australopithecus has been reconstructed using computer graphics in many documentaries.
The most famous fossil of the Afar Australopithecus is a partial skeleton, nicknamed Lucy (3.2 million years old), found by Donald Johanson and colleagues, who repeatedly played the Beatles song "Lucy in the Diamond Sky" during their work.
Discovery history
Fossils of Australopithecus afarensis have only been found in East Africa. Although the Laetoli area is the type locality for the Afar Australopithecus, the most extensive remains attributed to this species are found in Hadar, the Afar region of Ethiopia, including the aforementioned partial skeleton of "Lucy".
Compared to modern and extinct great apes, A. afarensis had shortened canines and molars, although they are still relatively larger than those of modern humans. Photos of the Afar Australopithecus in full growth (or rather, its reconstructions) show that these animals were much lower than modern humans. A. afarensis also has a relatively small brain (about 380-430 cm3) and a prognathic facial structure with protruding jaws.
Bipedalism
Significant debate in the scientific world has been mainly about the locomotor behavior of the Afar Australopithecus. Some studies suggest that A. afarensis was almost exclusively bipedal, while others have suggested that these creatures were partially arboreal. The anatomy of the arms, legs, and shoulder joints largely corresponds to the latter interpretation. In particular, the morphology of the scapula appears to be ape-like and very different from that of modern humans. The curvature of the fingers and toes (phalanges) approximates that of modern apes and suggests their ability to effectively grasp branches and climb trees. Alternatively, downsizingthe big toe, and therefore the loss of the ability to grasp objects with the feet (a feature of all other primates), suggests that A. afarensis has lost the ability to climb.
A number of features in the skeleton of the Afar Australopithecus strongly reflect bipedalism. In addition, some researchers even earlier assumed that bipedalism developed long before A. afarensis. In general anatomy, the pelvis is much more human-like than ape-like. The iliac bones are short and wide, the sacrum is also wide and is located directly behind the hip joint. A strong attachment to knee extension is evident. While the pelvis is not fully human-like (being markedly wide or ramified, with laterally oriented iliac bones), these features indicate a structure that can be considered radically remodeled specifically to accommodate bipedalism to this animal's locomotor repertoire.
Ecology
Climatic changes about 11-10 million years ago affected forests in East and Central Africa, setting periods when gaps in forest branches prevented normal life near the tree canopy, as animals could not even properly hide from the rain. During such periods, protogominids may have adopted vertical walking for ever-increasing land travel, while the ancestors of gorillas and chimpanzees continued to specialize in climbing up vertical tree trunks and lianas with bent hips and low knees. This isdifferential development within the larger hominid community has resulted in A. afarensis being adapted to vertical bipedalism for extensive hiking, still using small tree climbing skills of course. However, the protogominids and ancestors of chimpanzees and gorillas were the closest relatives, and they shared similar anatomical features, including identical wrists.
Earliest hominids
Some studies suggest an upright spine and predominantly upright body structure even in primates belonging to the early Miocene species M. bishopi 21.6 million years ago, the earliest human primates. Known from fossils found in Africa, Australopithecus are the group from which the ancestors of modern humans emerged. It is worth noting that the term "Australopithecine" often covers all early hominid fossils from about 7 million to 2.5 million years ago, as well as some later hominids that lived from 2.5 to 1.4 million years ago. After this period, Australopithecus is already considered extinct.
Sexual dimorphism and social behavior
One of the best indicators of the social behavior of extinct fossil species is the difference in size between males and females (sexual dimorphism). Through comparison with the behavior of modern apes and other animals, the reproductive behavior and social structure of the Afar can be assumed.australopithecines. One difficulty is that the average body size difference between male and female A. afarensis varies greatly from skeleton to skeleton. Some suggest that the males are significantly larger than the females and slightly similar in appearance to gorillas and orangutans. If A. afarensis exhibits the same relationship between sexual dimorphism and social group structure as modern gorillas, then these creatures may have lived in small family groups that included one dominant male and several breeding females. Other studies have shown that female and male Afar/African Australopithecus do not differ much in size - thus, in this respect, they were more similar to modern humans. Much larger than modern day monkeys.
Afar Australopithecus: traces of material culture
For a long time, no known discovered stone tools were associated with A. afarensis, and paleoanthropologists generally believed that stone artifacts only belonged to hominids that appeared after 2.5 million years ago. However, a 2010 study suggested that some early hominin species ate meat by cutting it off animal carcasses with primitive stone tools.
Further finds at Afar, including many hominid bones in the area, led Johanson and White to speculate that individuals from the Koobi Fora region matched those from Afar. In other words, Lucy was not unique in terms of bipedalism and flatness.face shapes - these features originated in many Afar Australopithecus living in this region.
Contemporary hominids
In 2001, Mike Leakey proposed the introduction of a new genus and species for a fossil skull, KNM WT 40000. The fossil skull appears to have a flat face, but is heavily fragmented. It has many other characteristics similar to the remains of A. afarensis. It is still the only representative of its species and genus, and its owner lived approximately in the same period as the Afar Australopithecus.
Another new species, named Ardipithecus ramidus, was found by Tim White and colleagues in 1992. It was a fully bipedal animal that lived between 4.4 and 5.8 million years ago, but appears to have lived in a forest environment.
