With the discovery of a species called Australopithecus afarensis, based on the famous Lucy skeleton, the most likely identity of these prehistoric strollers was established.

The specimen is older and much more complete than the "Lucy" skeleton found in Ethiopia in 1974.

This represents the earliest indisputable evidence of hominid bipedality, and it is usually attributed to Australopithecus afarensis, the species to which the famous "Lucy" skeleton belonged.

For two decades, the earliest known hominid was a species represented most famously by the Lucy skeleton.

Of the four fossil species examined, only Australopithecus afarensis, the species associated with the famous "Lucy" skeleton, failed the rule of thumb.

It was there in 1973 that he discovered the three-million-year-old Lucy skeleton, then the earliest known hominid, which was given the scientific name of Australopithecus afarensis.

From the Lucy skeleton, it is clear that A. afarensis was apelike but walked upright, much like modern humans, and apparently had been doing so for a long time.

They found it in early Homo specimens, but not in Australopithecus, the genus that lived more than three million years ago and included the 3.2-million-year-old Lucy skeleton.

Such a controversy has swirled around the Lucy skeleton.

The famous "Lucy" skeleton had everything paleontologists could hope for - except a head.