Palaeontologist Tim Ewin is standing in a quarry, recalling the calamity that's written in the rocks under his mud-caked boots.... ...The misfortune that struck this place 167 million years ago has delivered to him an extraordinary collection of fossil animals in what is unquestionably one of the most important Jurassic dig sites ever discovered in the UK.... ...The quantities involved are astonishing. Not hundreds, not thousands, but perhaps tens of thousands of these animals that scientists collectively call "the echinoderms". It's a great name, derived from the Greek for "hedgehog", or "spiny", "skin". What is a sea urchin, if not...