Conservation and photogrammetry of subfossil Quaternary walrus (Odobenus rosmarus) from the Bay of Fundy, Canada

Abstract

We describe a simple, inexpensive approach to the conservation and preservation of the subfossil cranium and tusks of a Quaternary (c. 2,900-12,800 years BP) walrus (Odobenus rosmarus) dredged from salt water. Ideally, wet specimens should be kept immersed in seawater until the treatment process is initiated. Regardless, it is critical that specimens not be permitted to dry out prior to desalination. Desalination was accomplished by gradually replacing sea water with fresh tap water, followed by controlled, slow drying over more than 530 days. Spalling was restricted to the tusks and occurred mainly between days 293-300, requiring surface consolidation with a dilute polyvinylacetate solution. The specimens were sufficiently stabilized for geology collections storage following the 591-day process. The use of photogrammetry to produce a 3D digital image of the partial walrus cranium with tusks permitted us to minimize the necessity of future handling and conservation and to preserve details of overall morphology and meristics useful for both research and public exhibition.