The Human Family Tree - Australopithecus group
The Australopithecus group of Human Ancestor
Early hominins (humans and their distant extinct cousins) known as the australopiths existed in Africa between 4.1 and 1.4 million years ago. The Species in this group of early humans generally walked upright but they also climbed trees. They were formerly called as the australopithecines, but they are not a "natural" group—in other words, they are not a "clade"—because they do not all descended from a single common ancestor. Instead, they are collectively categorized informally because almost all of them have the same adaptive grade, or set of adaptations.
They are specifically bipedal apes with, to a greater or lesser extent, enlarged canine and precanine teeth (postcanine megadontia), as well as other accompanying changes to their eating mechanisms. It is obvious that dietary modifications had a significant impact on their evolutionary history. They can also be identified by the absence of derived traits commonly found in members of the genus Homo, such as a large brain, a full range of adaptations for manual dexterity, and sophisticated tool use.
As a result, at least one or a few australopiths are directly related to the human lineage because Homo is almost probably descended from an australopith ancestor. Regardless, australopiths had a rich evolutionary history deserving of study independent of questions about our direct ancestry. They were numerous, geographically dispersed, anatomically diverse, and they experienced significant climatic change. Their story has dominated the evolution of humans for millions of years.
See how the evolution of humans began by reading about the Australopithecus species listed below:
1. Australopithecus anamensis
Discovery Date: 1995
Where Lived: Eastern Africa (Lake Turkana, Kenya and Middle Awash, Ethiopia)
When Lived: About 4.2 to 3.8 million years ago
OVERVIEW:
Both ape and human characteristics can be observed in Australopithecus anamensis. An increased region of bone at the upper end of the tibia (shin bone) and an ankle joint oriented in a manner similar to that of a human are signs of regular bipedal walking (bearing of body weight on one leg at a time). These people undoubtedly also climbed trees, as evidenced by their long forearms and wrist bone characteristics. The skull combines some more derived traits, like cheekbones that extend forward like in Paranthropus, with some more derived features, including a protruding face and a long, narrow braincase.
2. Australopithecus afarensis
Discovery Date: 1974
Where Lived: Eastern Africa (Ethiopia, Kenya, Tanzania)
When Lived: Between about 3.85 and 2.95 million years ago
Paleoanthropologists have found bones from more than 300 members of the Australopithecus afarensis species, one of the best-known and longest-living early human species. This species lived for more than 900,000 years, which is more than four times as long as our own species has existed. It was discovered between 3.85 and 2.95 million years ago in Eastern Africa (Ethiopia, Kenya, and Tanzania). It is well known from the sites of Dikika, Ethiopia (the skeleton of a kid from Dikika), Hadar, Ethiopia ('Lucy,' AL 288-1 and the 'First Family,' AL 333), and Laetoli (which contains fossils of this species as well as the earliest known bipedal footprint traces).
Children of Australopithecus afarensis, like chimpanzees, grew quickly after birth and matured before modern humans. This meant that Australopithecus afarensis had a shorter period of development than contemporary humans do, which left them with less time for parental guidance and early socializing.
Having both ape and human traits, Australopithecus afarensis had long, strong arms with curved fingers that were suited for climbing trees as well as apelike face proportions (a flat nose, a strongly projecting lower jaw), a small braincase (typically less than 500 cubic centimeters, or about 1/3 the size of a modern human brain), and a small brain. Like all other early humans, they possessed small canine teeth, a body that stood on two legs, and they frequently walked erect. They were able to endure for nearly a million years while climates and surroundings changed thanks to their adaptations for living both in trees and on the ground.
3. Australopithecus garhi
Discovery Date: 1990
Where Lived: Eastern Africa (the site of Bouri, Middle Awash, Ethiopia)
When Lived: About 2.5 million years ago
OVERVIEW:
Although a partial skeleton discovered nearby, from roughly the same stratum, is typically included as part of the Australopithecus garhi sample, the species is not extensively described and is only known from one fossilized cranium and four other skull fragments. Even if long, strong arms were still present, the attached incomplete skeleton shows a longer femur (in comparison to other Australopithecus specimens, such "Lucy"). As a result, bipedal walking might have evolved to involve longer strides.
4. Australopithecus africanus
Discovery Date: 1924
Where Lived: Southern Africa (South Africa)
When Lived: About 3.3 to 2.1 million years ago
Height: Males: average 4 ft 6 in (138 cm); Females: average 3 ft 9 in (115 cm)
Weight: Males: average 90 lbs (41 kg); Females: average 66 lb (30 kg)
OVERVIEW:
With a mix of human- and ape-like traits, Australopithecus africanus had physical similarities with Australopithecus afarensis. Australopithecus africanus possessed somewhat ape-like characteristics, such as relatively long arms and a sharply sloping face that protrudes from behind the braincase with a noticeable jaw, but it also had larger brains and smaller teeth than Australopithecus afarensis. Like Australopithecus afarensis, Australopithecus africanus' pelvis, femur (upper leg), and foot bones show that it moved on two legs, but its shoulder and hand bones show that they were also well-suited for climbing.
READ MORE ABOUT OTHER HUMAN ANCESTOR GROUPS:
3. Homo Group
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