Australopithecus anamensis

***Australopithecus anamensis*** is a species of _Australopithecus_. Its scientific name is abbreviated as **_A. anamensis**._

_A. anamensis_ is the earliest known australopithecine species. It lived from around 4.3 million years ago to around 3.8 million years ago.

_A. anamensis_ lived in East Africa. Paleoanthropologists have found over 100 _A. anamensis_ fossils in Kenya and Ethiopia, from 20 separate individuals.

## Name

The name _Australopithecus_ comes from the Latin word _australo_ (meaning ‘southern’) and the Greek word _pithecus_ (meaning ‘ape’).

The word _anamensis_ is based on the word _anam_, which means "lake" in the Turkana language. (This language is spoken in the area where _A. anamensis_ fossils were first discovered.) The word "lake" here refers to how _A. anamensis_ once lived next to lakes.

Together, the name _Australopithecus anamensis_ means "southern ape of the lake."

## Evolution

In human evolution, _Australopithecus anamensis_ is the intermediate species between _Ardipithecus ramidus_ and _Australopithecus afarensis_. This means that _A. anamensis_ descended from _Ardipithecus ramidus,_ and is the ancestor of _A. afarensis_.

Even though _A. anamensis_ evolved into _A. afarensis_, it did not replace it. The two species existed at the same time for at least 100,000 years.

## Description

The location of _A. anamensis_ fossils show that this species lived in forests and woodlands that grew around lakes.

_A. anamensis_ had a combination of human-like and ape-like traits. It was bipedal: it regularly walked upright. However, its long arms and wrist bones suggest that it also spent time climbing trees. It may have sometimes walked on its knuckles.

Based on fossils, scientists estimate that _A. anamensis_ was about the same size as modern chimpanzees. Like in modern gorillas and orangutans, females were much smaller than males. (This is called sexual dimorphism.)

Only one _A. anamensis_ skull has been found. That individual had a small brain, smaller than _A. afarensis_.

### Diet

Based on analysis of wear patterns on fossil teeth, _A. anemensis_ had about the same diet as a modern gorilla. Their diet stayed the same regardless of what environment they lived in. _A. anamensis_ mostly ate plants, including both fruits and tougher foods like nuts.

### First specimen

The first fossilized specimen of the species, though not recognized as such at the time, was a single arm bone. It was found in Pliocene strata in the Kanapoi region of East Lake Turkana by a Harvard University research team in 1965. The specimen was tentatively assigned at the time to _Australopithecus_ and dated about four million years old.

### 1987 specimen

Little additional information was uncovered until 1987, when Canadian archaeologist Allan Morton (with Harvard University's Koobi Fora Field School) discovered fragments of a specimen sticking out of a hillside east of Allia Bay, near Lake Turkana, Kenya.

### Allia Bay site

Six years later the London-born Kenyan paleoanthropologist Meave Leakey and archaeologist Alan Walker excavated the Allia Bay site and uncovered several additional fragments of the hominid, including one complete lower jaw bone which closely resembles that of a common chimpanzee (_Pan troglodytes_) but whose teeth are much more similar to those of a human. In 1995, Meave Leakey and her associates, taking note of differences between _Australopithecus afarensis_ and the new finds, assigned them to a new species, _A. anamensis_, deriving its name from the Turkana word anam, meaning "lake".