Jurassic Period, 180 million years BP. A bifacial cut and polished section of ichthyosaur fossil vertebra. 868 grams, 26cm (10 1/4"). Property of a Leicestershire, UK, collector; ex UK market; from Kettleness, near Whitby, North Yorkshire, UK. Ichthyosaurs (Greek for 'fish lizard' - ichthus meaning 'fish' and sauros meaning 'lizard') were giant marine reptiles that resembled dolphins, in a textbook example of parallel evolution. They thrived during much of the Mesozoic era; based on fossil evidence, they first appeared approximately 245 million years ago and disappeared about 90 million years ago, about 25 million years before the dinosaurs became extinct. [No Reserve]