31 January, 2019
Today the grey whale, Eschrichtius gibbosus, is found only in the Pacific Ocean, but it was first discovered in 1859 as a fossil partial skeleton at Gräsö on the east coast of Sweden. Although it was recognised as a new species of whale in 1861 by a Swedish zoologist, Wilhelm Lilljeborg, it was not known how distinctive it was until John Edward Gray placed it in its own genus, Eschrichtius, in 1864. Since then at least 37 fossils of grey whale have been dug up or dredged from the sea in the North Atlantic, showing that the species was once widespread. Radiocarbon dating has shown that these range in age from c.10,000 years ago to only 300 years ago.
Although bones from whales often turn up in archaeological sites, they can be very difficult to identify, because they are often only fragments or they have been modified to serve some purpose, such as a lintel above a door way. Ancient DNA can be used to identify these fragments, but the success rate is not high and the technique is quite expensive. Dr Mike Buckley at Manchester University has been pioneering another method for identifying archaeological bone. Instead of DNA, he extracts collagen, which is a protein that makes up a large proportion of our bones. Species or groups of species have different collagen fingerprints, which allow identification.
Grey whale vertebrae. Credit: University Museum of Bergen.
The University Museum of Bergen contains more than 7,000 cetacean (whale, dolphin and porpoise) archaeological bone fragments, but less than 20% of these have been identified to species. Dr Buckley selected 373 mostly unidentified bones for identification using collagen fingerprinting. Knowing that there was a possibility of grey whale among the fragments, Dr Buckley contacted National Museums Scotland to ask for our assistance in obtaining a sample of grey whale bone from the Natural History Museum of Los Angeles County to act as a reference sample for a collagen fingerprint for this species. Sadly we do not have a grey whale skeleton (yet), so this loan was essential. Two vertebrae from the same whale found in Kringlevågen in Solund on the west coast of Norway were identified as being from a grey whale and this was subsequently confirmed by ancient DNA analysis. Radiocarbon dating showed that this grey whale, the most northerly recorded from the Atlantic, stranded in Norway 1,680-1860 years ago.
National Museums Scotland is a collaborator in a research partnership, The Norse Use of Marine Mammals in the Medieval North Atlantic, which is led by Dr Vicki Szabo of Western Carolina University and funded by the National Science Foundation in the USA. Collagen fingerprinting is currently being used by Dr Buckley in conjunction with ancient DNA to reveal the identities of cetacean bones found in Norse archaeological sites from Iceland and Greenland. For the first time all that archaeological bone has a story to tell about how the Vikings exploited and used marine mammals around 1,000 years ago.