This 30 January 2019 video, made in London, England says about itself:
Walruses are known for their impressive tusks. But they have another feature that is equally impressive.
Richard Sabin, Principal Curator of Mammals at the Museum, explains.
An international collaboration of scientists has for the first time used ancient DNA analyses and C14-dating to demonstrate the past existence of a unique population of Icelandic walrus that went extinct shortly after Norse settlement some 1100 years ago. Walrus hunting and ivory trade was probably the principal cause of extinction, being one of the earliest examples of commercially driven overexploitation of marine resources: here.