Perseverance yields the discovery of an infant hominin skeleton.
The Afar basin in northeastern Ethiopia has proved to be a fertile hunting ground for palaeontologists. In 1974, the region yielded the first remains of the genus Australopithecus in the shape of Lucy (A. afarensis). But the region is not the easiest place to conduct research, as it is caught up in conflicts between local tribes.
Despite the potential risks, Zeresenay Alemseged was determined to dig in the area — and his efforts have been richly rewarded (see page 296). Alemseged, a palaeoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, is a native Ethiopian, and he set about winning the support of the Afar locals as guides and guards to help him in his work.
The area Alemseged focused on is known as Dikika, and is some 10 kilometres from where Lucy was discovered. In late 2000, his team was lucky enough to spot a skull sticking out of the sand. It turned out to be a very significant find. It was the intact skull and a partial skeleton of a 3-year-old A. afarensis girl: the most complete, earliest specimen ever found, and it promises to supplant the 3.2-million-year-old Lucy for the title of the world's most famous hominin remains.
The sandstone preserved the face and a cast of its skull cavity — allowing researchers a glimpse of her appearance and a measure of brain volume. That first foray also revealed shoulder blades, collar bones, ribs and spinal column, hinting that there was more to unearth.
After depositing the first batch of fossils at the National Museum of Ethiopia, Alemseged returned to Dikika each year. Those subsequent trips yielded a humerus, fingers, both knee caps, the thigh and shinbone from both legs, and an almost complete foot, representing about 50% of the entire skeleton.
Besides annual rains that sweep aside sediment, Alemseged relied on other researchers and assistants to probe the sands. “You simply can't do this alone — you need a multidisciplinary team of scientists,” he says.
Between trips, Alemseged separated and categorized the different elements of the skeleton. “For the past five years, I've spent most of my summer days describing the fossil and cleaning it under a microscope with dental instruments, because I decided not to use acid treatments that could destroy it,” he says.
His preliminary analyses will surely spark fresh debates over hotly contested issues. For example, was the species a tree climber? The shoulder joint indicates that the arm could have been raised above the shoulder — necessary for climbing. And the discovery of the hyoid, the horseshoe-shaped bone that supports the tongue, is the first evidence for a voice box in A. afarensis.
As well as analysing the specimen, Alemseged plans to name the girl to honour all those involved. “Given the conflicts in the region, I'd like to build consensus among the locals for a name that represents peace,” he says.