The investigators from the UAB have worked on an area of 60 metres squared, excavating a large area which has enabled them to reconstruct the way in which the people who inhabited the shelter lived. This system of working is not usual in archaeology since excavations are generally restricted to smaller earth movements. They have been able to recover archaeological materials from the Middle Palaeolithic attributable to Homo neanderthalensis, and from the Upper Palaeolithic, which corresponds to Homo sapiens, separated by sterile strata of sediment which allows their differentiation.
The exceptional conditions of conservation of these archaeological remains, which have remained unaffected by biological and geological changes, have meant that the materials used by each of these species has been conserved without the need for significant earth movements, contrary to that which has been indicated in other archaeological sites. This detailed analysis of the tool remains recovered allows major differences to be observed in the way in which they were made, implying that they were made by different species.
This is something that has also been recognised in other sites in Western Europe, and it goes to strengthen the hypothesis that the two species neither lived together nor interacted with each other, although they may have lived in the same geographical area during the period from 40,000 to 30,000 years, which is generally referred to as the Middle/Upper Palaeolithic ‘transition.’