Tim Ewin, a palaeontologist, is standing in a quarry and thinking back to the catastrophe that is depicted in the rocks beneath his mud-covered boots.
Fossilised seafloor animals from the Jurassic, all piled on top of each other
“They tried to protect themselves, adopting the stress position of pulling their arms in,” he continues. “But it was all in vain; you can see where their arms got snagged open, right up to the crown. They were pushed into the sediment and buried alive.
There’s a little smile creeping across Tim’s face, and he’s got reason to be happy. 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. We can’t be precise about the location of the excavation for security reasons, but you’ll recognise from the gorgeous, honey-coloured limestone that we’re somewhere in the Cotswold country.
Things have changed a bit since Jurassic times, though.
No quaint villages and dry-stone walls back then; these parts were covered by a shallow sea, maybe 20-40m deep. And it was a damn sight warmer than your traditional English summer. The movement of tectonic plates means Britain was roughly where North Africa is today. So you can imagine the types of creatures that would have been living on this ancient, near-tropical seafloor.
The fossils are in clay layers that intersperse the Cotswold limestone
Stalked animals called sea lilies were tethered to the bed in great “meadows”. Their free-floating cousins, the feather stars, were ambling by, looking to grab the same particles of food. And down in the sediment, starfish and brittle stars were feeling their way across the bottom with their fives arms, no doubt bumping into the occasional passing sea urchin or sea cucumber. It’s exactly this scene that’s preserved in the rocks of our mystery quarry. 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 an “underwater hedgehog“?
