Preparação físicoquímica de esqueleto submerso encontrado na Caverna Poço Azul Bahia

Abstract (English)

Fossil preparation is a detailed task, where any incorrect procedure can irreparably damage the piece. Some Brazilian authors developed a technique of preparation that separates the skeleton remains from the rock that surrounds them. Most studies of paleovertebrate fossil preparation, for example, are concentrated on the preparation of ichthyolites, therefore, it is necessary to develop more proprietary methods for the other groups of paleovertebrates. The material of this study was discovered submerged in a cavern, in Poço Azul do Milú, Bahia, Brazil. Among this material, a skeleton of a giant sloth, Eremotherium laurillardi (Lund, 1842), was found. This work consists of a description of the preparation of the above material. The first phase entailed cleaning and stabilizing the fossil with two baths of polyvinyl acetate dissolved in water. After this immersion, the fossils were to dry, so the water could evaporate and the composition harden in the pieces. The second phase was a restoration of the dislocated pieces. For this, polyvinyl acetate and cyanoacrylate glue, plaster of Paris and dentistry instruments were used. Because of the weight, rigidity and fragility of the material, the plaster was substituted for polyurethane to make the fossil accommodation beds. With the pieces stabilized, restored and accommodated, they could be more safely handled. Since the fossilization process occurred in a water setting, while still alive, the fossil material is well preserved and exhibits details of the morphology, which is not the case of other fossils of E. laurillardi, all found in dry settings, and suffering from interference of the karstic environment.