Auction introduction: Sotheby’s is pleased to present “Prehistoric Earth”, our first Natural History auction to take place in Hong Kong. On offer will be two exceptional fossil specimens: an incredibly rare juvenile Gryposaur from the Late Cretaceous period (approximately 100 million to 66 million years ago), as well as a remarkably well preserved skull of a Woolly Mammoth dating from the Pleistocene period (2.6 million – 10,000 years ago), featuring a striking pair of vivianite-swirled tusks, lending them a unique blue colour.