Restoration of volumetric reintegration on vertebrate fossil using dental baseplate wax and plaster

STELLA MARIS ALVAREZ

Londres

Simposio; Symposium of Palaeontological Preparation and Conservation 2020; 2020

The Geological Curators 'Group

https://www.geocurator.org/events/104-sppc/sppc2020-poster-gallery@OriginalGCG #sppc2020alvarezAt the Museum of Natural Sciences "Bernardino Rivadavia", I carried out an intervention on the specimen of Sclerocalyptus Ameghino, MACN-PV 18.107, from the Pleistocene of Buenos Aires province, Argentina. The scapulae were poorly preserved due to multiple fractures and parts of the bone were missing. First, small fragments were adhered to each other with cyanoacrylate. Some sections of scapulae were less than 4mm thick. The volumetric reintegration method was then used to complete the missing parts. Dental baseplate wax (useful in odontology and archaeology) was used to hold the filling material, which has thermoplastic properties. Wax was softened by immersing it in hot water because it is known that when wax is exposed to sources of dry heat, it melts too much on the surface and liquefies, filtering through the pores of the fossil, and is very difficult to remove. On the other hand, an advantage of immersion in hot water is that the wax softens homogeneously without reaching a liquid state, giving malleability and sticky viscosity. Once adhered wax was dry, successive small amounts of plaster were placed (using the dot technique) onto the wax near the bone until the missing layer was complete. This technique prevents plaster from sticking out (burrs). The main aim of this work is to shed light on a new plaster filling technique for incomplete and fragmentary fossils that are very thin, and which allows a functional and neat filling, without adverse consequences for the fossil.