A Swedish subfossil find of a bowhead whale from the late Pleistocene: shore displacement, paleoecology in south-west Sweden and the identity of the Swedenborg whale (Balaena swedenborgii Liljeborg, 1867)

Abstract

The Swedenborg whale Balaena swedenborgii Liljeborg, 1867, is a baleen whale species believed to have existed in the North Sea from the period when the inland ice melted around 13,000 before present (BP) until about 8000 years ago. The first bones attributed to this species were found in Sweden in 1705. When whale remains were discovered on the Swedish west coast during the extension work of a motorway extension, it was speculated that this could be a specimen of the extinct Swedenborg whale. The bones were found 72 m above the present-day sea level embedded in glacial mud. Shelly remains of marine organisms were present in the deposit surrounding the whale-fall, and sediments with the associated specimens were therefore collected for further analyses. We applied radiocarbon dating, thin sectioning, morphological analyses, ancient DNA typing and analyses of the associated shelly assemblage in an interdisciplinary effort to understand the circumstances of this fossil whale-fall. Our results show that the whale is not the putative species B. swedenborgii, but a bowhead whale Balaena mysticetus. The results also indicate that the whale must have been rapidly covered by glacial sediments, highlighting the speed of the deglacial process in the area.

Keywords::

• bowhead whale
• Greenland right whale
• Balaena mysticetus
• Balaena swedenborgii
• mtDNA control region
• petrographic thin section
• cetacean taphonomy

Acknowledgements

This study was possible thanks to the enthusiastic support of the road construction crew at SVEVIA, who first spotted the whale remains, helped with the excavation and now support the exhibition at Femstenaberg service station. We would also like to thank Julia Llewellyn-Hughes and Jacqueline Mackenzie-Dodds for sequencing and assistance in the lab, Göran Nilsson, Svante Lysén, Curt Fredén and Lou Schmitt for valuable discussion and input, and Kosterhavets national park for partially funding the 14C-dating. Funding for this research was provided by Formas, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (to C.A.), the Natural History Museum Strategic Innovation Fund (to C.A. and A.G.) and the Swedish Research Council (to T.G.D.).

Notes

^1. Present address: Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden.

^2. Present address: Plymouth University, School of Geography, Earth and Environmental Sciences, Plymouth, Devon, PL4 8AA, UK.

^3. Present address: Uni Research, Postboks 7810, N-5020 Bergen, Norway.

^4. Permission to cite C. Fredén was acquired.