Sierra de Atapuerca is a large limestone ridge located 15 Km east of Burgos in Northern Spain. The caves of this ridge contain some of the earliest evidence of human habitation in all of Europe. Some of the Sierra de Atapuerca fossils date back almost a million years. The area was originally discovered around a 100 years ago when a railway trench was built. This exposed several unique areas that paleontologists have been systematically excavating since 1976.
Literally thousands of prehistoric human fossils have been unearthed at the various sites in the Sierra de Atapuerca. Including what is thought to be a completely new species of prehistoric man (Homo antecessor). The most complete sample of Pleistocene hominids ever discovered was found here. In fact many of the fossils discovered have invalidated previous theories of both human evolution, and European prehistory.
The caves of the Sierra de Atapuerca have been occupied almost continually since the Pleistocene era. Right up until about 10,000 years ago. What this means is that paleontologists have the opportunity to study almost a million years of evolution in a single place. A large amount of fossils of early carnivorous mammals have also been uncovered in addition to all of the human remains.
There are six major sites at Sierra de Atapuerca. I will be covering each one in detail in some upcoming nodes. For now I will provide a quick overview of each one.
The Gran Dolina site is a large cave that is about 20 meters deep. The width is uncertain due to a partial collapse thousands of years ago. This cave was where the Homo antecessor fossils were discovered. Along with some early stone tools, and many herbivore and carnivore fossils. The herbivore fossils were without a doubt creatures that were hunted by the early humans. As indicated by many cut marks on the bones (without any of the tooth marks that a carnivore would have left).
The Galería cave was not occupied nearly as heavily as the Gran Dolina site (perhaps because of the poor natural lighting). The majority of the fossils and tools discovered here date from 120,000 to 450,000 years ago. The main function of this cave seemed to be as a resting, and scavenging area. Where early hominids would often visit the cave looking for any animal remains that may have been abandoned by the local carnivores.
The Penal cave belongs to the same system as the Gran Dolina. But they are independent channels. So far the archaeological record of Penal has been poor, to say the least. But researchers have learned quite a bit from sedimentary information gained from this cave.
Sima del Elefante
This site is just now being tested for excavation. Tests seem to indicate that the cave dates the early Lower Pleistocene. Further study and excavation of this cave are planned for the future.
Sala de los Cíclopes
The Sala de los Cíclopes is a small hall located before the acces to the Sima de los Huesos. So far there has been no evidence of any human occupation. However it was used by Pleistocene era bears as a hibernation chamber (which is probably why no humans occupied it). Partial excavation of this hall has begun.
Sima de los Huesos
This is 13 meter deep pit that opens into a small hall. This site appears to be some sort of graveyard. No tools have been found. But thousands of human remains have been discovered (all dating to at least 300,000 years ago). There is no trace at all of habitation, simply thousands of bones. The graveyard hypothesis is strengthened by lack of herbivore remains. Along with the low occurence of fractures, and the absence of tooth marks on the fossils that would be common if carnivores had been leaving these human remains behind. The current belief is that the Homo heidelbergensis population of the area was leaving their own remains in this pit. Although the opinion are divided over the reasons. It could be religous, or it could have been simply to get the bodies away from the settlement (to keep away the carnivores).