The preparation and conservation treatments of the Homo antecesor fossils

Abstract

We report the preparation and conservation work carried out on the human fossils from level TD6 (Gran Dolina) recovered in excavations from 2003 to 2007. Many of them, after excavation, were partially covered or even almost completely included in a compact and hard sediment strongly adhered to the surface, and they required a series of preparation work, without which in many cases, their study would not have been possible. The treatments made were technically simple (mechanical cleaning, consolidation, reconstruction), but they were developed under a strict methodology of conservation whose aim has been to recover and preserve the archaeopaleontological information. Besides the obvious retrieval of information itself, insofar as the fossils were uncovered, reassembled and strengthened, the preparation work of the Homo antecessor fossils has served to establish some criteria that we hope will help to settle the intervention methodology designed to treat similar material. Briefly, these proposed criteria consist of adapting the interventions to the needs of the research without contravening the conservation fundamental principles, such as the respect for the integrity of the material, the minimal intervention and the reversibility of products and treatments used. A key aspect in the work here reported is detailed documentation of the whole process, recording both the products and techniques used in interventions, as well as the fossils in the different phases of the treatment (before, during, after treatment). The documentation allows understanding the decisions made about treatment and also to undo the treatment in the future (e.g. to remove consolidants or glues). Additionally, the documentation also helps to retrieve more information, which may available only before or during the reconstruction of the fossils (e.g. detailed images of the fracture planes before reassembling a fossil); it also helps to interpret part of the changes originated by the treatment (e.g. distinguish between marks caused by the preparation work and traits of taphonomic interest). With this work we aim to show that the result of the preparation and conservation (hands on) treatments is not the simply recovery of a fossil (to have a clean and reconstructed specimen) but to recover and to save all the information available during all the treatment.