Fossil hunters have found remains of a probable
direct ancestor of humans which lived more than four million years
The specimens of this ancient creature are helping
bridge a long gap during a crucial phase of human evolution. Professor
Tim White of the University of California, Berkeley, and colleagues
unearthed the cache of fossils in the Middle Awash region of Ethiopia.
They describe the finds, which belong to the species
Australopithecus anamensis, in the journal Nature.
Australopithecus is an important ancient genus of humanlike
creatures, or hominids. Our own genus, Homo, is widely thought
to have evolved from this group. So the relationship between
Australopithecus and even earlier bipedal hominids is crucial
to understanding where we all ultimately come from.
When placed together with other fossils from the same
general area of Ethiopia, the 4.1-million year-old anamensis
specimens appear to establish an evolutionary succession between
earlier and later species.
'The fact [that] anamensis is sandwiched
between earlier and later hominids is what is really significant
about this Ethiopian sequence,' said Tim White.
The finds close the gap between a more ancient species
known as Ardipithecus ramidus, which is found at 4.4 million
years and a later species known as Australopithecus afarensis,
which is present in the Middle Awash 3.4 million years ago.
Australopithecus anamensis is intermediate
between the two, not only chronologically but also in terms of its
anatomy. The anamensis species is not new but, say the
researchers, 'this is the first time that these three species have
been shown to be time-successive in a single place'.
This reconstruction of Australopithecus anamenis shows a
fairly chimp-like facial type, but this creature walked upright,
much more like a human than an ape