Homo antecessor: The Gran Dolina Fossils of Atapuerca, Spain

Homo antecessor is an extinct human species known from fossils found at Gran Dolina, a cave site in the Sierra de Atapuerca near Burgos in northern Spain. The remains, dated to roughly 900,000 to 800,000 years ago, were named in 1997 and are among the oldest human fossils in western Europe. They show a surprisingly modern-looking face, clear evidence of cannibalism and a puzzling place in the human family tree.

Background: a railway cutting full of caves

The Sierra de Atapuerca is a low limestone hill riddled with caves. In the 1890s a British mining company cut a trench through it for a railway to carry coal and iron ore. The cutting sliced through several ancient caves filled with sediment, including Gran Dolina, exposing layers rich in bones and stone tools.

Scientific interest grew slowly. In 1976 a student found human fossils in a nearby cave, the Sima de los Huesos, and from 1978 the palaeontologist Emiliano Aguirre began systematic excavations. From 1991 the project was led by three Spanish researchers: the palaeoanthropologists Juan Luis Arsuaga and José María Bermúdez de Castro and the archaeologist Eudald Carbonell.

The 1994 discovery in TD6

Gran Dolina contains about 18 metres of sediment divided into levels numbered TD1 to TD11 from bottom to top. In 1994 the team dug a small test pit, a few square metres across, deep into the sequence to check what the lower levels contained.

In July 1994, in level TD6, they found human remains. The fossil-bearing layer became known as the Aurora stratum, after the archaeologist Aurora Martín, who made one of the first finds. Within a couple of field seasons the small pit had yielded dozens of human fossils, and later excavations raised the total to more than 170, belonging to at least six and probably around a dozen individuals.

Most of the remains belonged to children and adolescents. The most famous is ATD6-69, part of the face of a boy about 10 to 11 years old, often called the “Boy of Gran Dolina”.

Dating the Aurora stratum

The age of TD6 rests on several methods. Above it, in level TD7, the sediments record the last major reversal of the Earth’s magnetic field, the Matuyama-Brunhes boundary, dated to about 780,000 years ago. TD6 therefore must be older.

Electron spin resonance and uranium-series dating of teeth and quartz grains, along with luminescence dating, place TD6 at roughly 900,000 to 800,000 years ago. A figure of about 850,000 years is often cited.

Naming Homo antecessor in 1997

In May 1997 Bermúdez de Castro, Arsuaga, Carbonell and colleagues published the fossils in Science as a new species, Homo antecessor, from the Latin for “one who goes before”. They argued that it combined primitive features, such as the shape of some teeth and a strong brow, with a strikingly modern face.

The boy’s face, ATD6-69, has a hollow below the cheekbone, called a canine fossa, and a lightly built midface similar to that of modern humans. The team proposed that Homo antecessor might be the last common ancestor of Neanderthals and modern humans, having descended from African Homo erectus or a related species.

Brain size is hard to estimate from the fragments, but a partial frontal bone suggests a capacity of over 1,000 cubic centimetres. Adults were probably around 1.6 to 1.8 metres tall.

Evidence of cannibalism

The most dramatic finding at Gran Dolina concerns how the bodies were treated. Many of the human bones carry stone-tool cut marks, scraping marks, breakage to extract marrow and even signs of chewing. The same patterns appear on the bones of deer, bison and other animals from the layer.

The researchers concluded that the human remains had been butchered and eaten in the same way as game. Because most of the victims were young, Carbonell and colleagues argued in 2010 that cannibalism may have been a regular practice, perhaps linked to conflict with neighbouring groups, rather than a response to famine. Other researchers remain cautious about interpreting motives from bones alone.

Whatever the reason, Gran Dolina provides some of the oldest clear evidence of cannibalism in the human lineage.

Tools and way of life

The stone tools from TD6 are simple flakes and cores made from local flint, quartzite, limestone and sandstone. They belong to the core-and-flake tradition sometimes called Mode 1, similar to the Oldowan of Africa, and there are no hand axes. Cut marks show that the inhabitants butchered a wide range of animals, including deer, horses, bison and rhinoceros.

Pollen and animal remains suggest a fairly mild, wooded environment with open areas nearby. The people of Gran Dolina were hunter-gatherers living in a landscape rich in game, at the edge of a continent only just being settled by humans.

A puzzling place in the family tree

The claim that Homo antecessor was the common ancestor of Neanderthals and modern humans was controversial from the start. Some researchers argued that the modern-looking face reflected the boy’s youth, and that the fossils might belong to a local European population or to Homo heidelbergensis.

In 2020 a team led by Frido Welker and Enrique Cappellini analysed ancient proteins preserved in the enamel of a Homo antecessor tooth, published in Nature. The results placed Homo antecessor as a close sister lineage to the group that gave rise to Neanderthals, Denisovans and modern humans, rather than its direct ancestor.

Other early Europeans add to the picture. A jaw from Sima del Elefante, also at Atapuerca and dated to about 1.2 to 1.1 million years ago, is even older but has not been assigned to a species. Footprints at Happisburgh in England, dated to roughly 850,000 to 950,000 years ago, may have been left by a population similar to Homo antecessor.

Myths and facts

Myth: Homo antecessor was the first human in Europe. It is among the earliest, but stone tools and the Sima del Elefante jaw at Atapuerca, as well as tools from sites in southern Spain and Italy, suggest that humans reached Europe somewhat earlier, perhaps more than 1.2 million years ago.

Myth: the people of Gran Dolina ate each other because they were starving. The layer contains plenty of animal bones, so famine is not an obvious explanation. The motive, whether conflict, ritual or opportunity, remains unknown.

Fact: the modern face is debated. Because the best-preserved face belongs to a child, some researchers argue that its modern look may partly reflect youth rather than a close relationship to Homo sapiens.

Timeline

• c. 900,000 to 800,000 years ago: Humans living at Gran Dolina leave remains in level TD6.
• c. 780,000 years ago: The Matuyama-Brunhes magnetic reversal is recorded in level TD7.
• 1890s: A railway trench cuts through the Sierra de Atapuerca caves.
• 1978: Emiliano Aguirre begins systematic excavations at Atapuerca.
• 1994, July: Human fossils are found in level TD6 of Gran Dolina.
• 1997, May: Homo antecessor is named in Science.
• 2000: The Archaeological Site of Atapuerca is listed by UNESCO.
• 2020: Ancient tooth proteins place Homo antecessor as a sister lineage of later humans.

Why it matters

Homo antecessor shows that humans were living in western Europe more than 800,000 years ago. Its modern-looking face, its cannibalism and its position close to the root of the Neanderthal and modern human lineages make Gran Dolina one of the most important sites for understanding early Europeans.