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Anthropology

The ‘new’ Atapuerca skull

The archaeological site of the Sima de los Huesos in Spain’s Burgos province has revealed shards from a skull a half million years old.

JULY 27, 2010 | ALICIA RIVERA

Javier Trueba / Madrid Scientific Films

The reconstruction of the skull, according to the Atapuerca scientists, will take a year at least, given the bone’s fragile state. In any case, this will not be the first skull to be put back together. Since the beginning of the systematic excavations of the Sima de los Huesos site a quarter of a century ago, the cranial remains of 17 individuals, some of which were found in small fragments, have been recovered. The new finding, however, could be one of the most complete, possibly the second or third most complete, says Juan Luis Arsuaga, co-director of the excavation and lead researcher at the site.

So far, the most famous skull in the Atapuerca collection is still the No. 5, nicknamed Miquelón, an ancient skull which was presented to the world on the cover of the journal Nature in 1993 and which now hangs in the newly opened Museum of Human Evolution in Burgos. It is the best preserved skull of its kind in the world. But equally important are the No. 4 (Agamenón), another adult, and No. 6, of a child. The skulls are revered trophies of paleontology for the amount of information they have provided.

The harvest of 2010

Along with the new skull fragments, which first began appearing in 2009, Atapuerca has just ended the 2010 season with yet another excellent harvest of relics from the distant past. Two stone tools found at “the Elephant” site, which may be more than 1.2 million years old and therefore would become the oldest traces of human occupation in the area, and thousands of animal fossils from the Gran Dolina site, which will inform scientists about the fauna and environment of the hominids of the past and their food-gathering techniques, have all been found this year. Also, from much more recent times of only five thousand years ago, archeologists have found a set of tombs in the area of El Mirador site.

In the past couple of decades, excavations at Atapuerca have grown significantly under the direction of Arsuaga, Eudald Carbonell and Jose María Bermúdez de Castro, exploiting the vast scientific potential of the deposit. In addition to the treasures offered in the form of unique human fossils such as the Sima collection or the remains of Homo antecessor, both discovered in 1994 and dating back almost 800,000 years, corresponding to one of the oldest inhabited sites of Europe, the Burgos sierra has been witness to a continuous sequence of the record of humanity’s past.
Arsuaga and his team have extracted more than 6,500 human fossils from the cave

The Atapuerca site is a set of caves in an area where for more than a million years different human species have succeeded one another throughout history. In the cave called El Portalón de Cueva Mayor there are fire pits and pottery from just 4,000 years ago. That is, remnants of “yesterday’s” prehistoric man, obviously of our own species, Homo sapiens sapiens, are resting there.

The other end of the spectrum of human time is occupied, for the moment, by Homo antecessor, represented by a 1.2 million-year-old jaw and the nearly 800,000-year-old remains found at the Gran Dolina site. At the midway point are the preneandertales (Homo heidelbergensis) found at the Sima de los Huesos site.

From railroads to the history books

It all started over a century ago, when the construction of an unfinished mining railway opened a trench in the mountains of Burgos and cut through a set of caves, exposing their sediments. Decades later, scientists are still examining with extreme care the sediments in The Elephant, Mirador and Gran Dolina caves in search of prehistoric remains.

Hominid fossils always cause excitement in any paleontologist regardless of where they are discovered, even if they amount to nothing more than a few bones. The find of a skeleton, albeit incomplete, and is a huge event, and if it includes more than one individual, then the archaeologists go directly into the history books.

But the Sima de los Huesos site breaks the mold of paleoanthropology. In just over two decades, Arsuaga and his team have extracted more than 6,500 human fossils from the cave. Each and every one of the bones of the skeleton are represented, and there are over thirty individuals of all ages and of both sexes. There is no other collection in the world even remotely comparable.

A diverse group of thirty individuals offers scholars a unique opportunity to study not only their physical characteristics but also to venture into what has been called paleobiology, i.e. the study of the different traits of human groups, their illnesses, their development patterns or vestiges of their behavior, such as caring for the sick and the elderly.

DESCENDING INTO THE CAVE
To reach the Sima de los Huesos site, one must travel a good way into the cave and then climb down about 15 feet to the cave’s bottom. This is where, accidentally or not, more than half a million years ago those bodies that later became fossils, along with the bears found there, came to their final resting place. For a few weeks every summer a handful of paleontologists go down to the site and recover more bones. Ignacio Martínez is the great expert who, armed with patience, small brushes, tweezers, a syringe with water and little more, separates each bone that comes to light from the sediment. The team exhaustively documents every step taken in the excavation. Following the annual campaign, with the harvest, the scientists are going to their labs, where they spend months cleaning up the fossil, classifying and, above all, studying. It is slow work, but this science is not worth the rush. And what have these specialists is very clear that it is pointless to shovel out the fossils and can analyze in depth. They know that the Sima, and Atapuerca, give a lot of work to future generations of paleontologists.

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