Atapuerca is a World Heritage Site located in Burgos province, Spain. The construction of a railroad at the end of the 19th century, cutting through the foothills of the Sierra de Atapuerca, led to the discovery of several hominid sites. In 1910, the archaeologist Jesus Carballo discovered the Bronze Age site and paintings in the Cueva Mayor, known as the Portalon. In 1964 and 1966, Francisco Jordâ carried out excavations, which led to the first estimation of the antiquity of the sites in the Trinchera. Based on the faunal analysis done by Juan F. Villalta, an age of 500,000 years ago was estimated. In 1976, Trinidad Torres undertook an excavation and entered in the Sima de los Huesos in search of bear remains. Among the bones removed were human fossils: mandible, teeth, and cranial fragments. Torres took the human fossils to his doctoral advisor, the paleontologist Emiliano Aguirre, and based on the bears’ remains placed the site within the Middle Pleistocene.
Due to the importance of the human remains, Aguirre organized a multidisciplinary group to excavate the main sites, and after he retired, the studies were codirected by Juan L. Arsuaga, José M. Bermudez de Castro, and Eudald Carbonell. Since 1978, very relevant human remains have been found by this multidisciplinary group in the main sites: Trinchera Dolina, Trinchera Galena, Sima de los Huesos, Portalon de Cueva Mayor, Trinchera Elefante, and Mirador.
Trinchera Dolina excavations in 1990 yielded a lot of vertebrate bones and in 1993 intensive excavations began of an area of 6 sq m. In 1994, several human fossils were discovered: a handful of upper and lower teeth, a large cranial fragment, and a mandible with a molar wisdom tooth in the process of erupting. Furthermore, 36 human fragments were recovered of at least six individuals. Based on micromammals and magnetostratigraphy, the level was dated of 780,000 years ago. In 1997, a new human species was defined: Homo antecessor, the species that discovered Europe.
Sima de los Huesos is the other most important site of Atapuerca. It is a small cavity at the end of a ramp, which is accessed by a 13-meter vertical shaft, after traversing half a kilometer of difficult passages from the current entrance to Cueva Mayor. The Sima de los Huesos is one of the most productive paleanthropological sites in the world. Since 1987, at least 28 different individuals had been identified as Homo heidelber-gensis. Several very well preserved and almost complete craniums, mandibles, pelvises, femurs, hands, and feet have a mixture of ancient and modern characteristics.
Some are similar to their Neandertal descendants and others to their ancestors the first Europeans.
- Arsuaga, J. L., Martinez, I., Gracia, A., Carretero, J. M., & Carbonell, E. (1993). Three new human skulls from the Sima de los Huesos Middle Pleistocene site in Sierra de Atapuerca, Spain. Nature, 362, 534-537.
- Bermudez de Castro, J. M., Arsuaga, J. L., Carbonell, E., Rosas, A., Martinez, I., & Mosquera, M. (1997). A hominid from the Lower Pleistocene of Atapuerca, Spain: Possible ancestor to Neandertals and modern humans. Science, 276, 1392-1395.
- Carbonell, E., Bermudez de Castro, J. M., Arsuaga, J. L., Diez, J. C., Rosas, A., Cuenca-Bescos, G., Sala, R., et al. (1995). Lower Pleistocene Hominids and artifacts from Atapuerca-TD6 (Spain). Science, 269, 826-830.