Trilobite: Eyewitness to Evolution
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With Trilobite, Richard Fortey, paleontologist and author of the acclaimed Life, offers a marvelously written, smart and compelling, accessible and witty scientific narrative of the most ubiquitous of fossil creatures.
Trilobites were shelled animals that lived in the oceans over five hundred million years ago. As bewilderingly diverse then as the beetle is today, they survived in the arctic or the tropics, were spiky or smooth, were large as lobsters or small as fleas. And because they flourished for three hundred million years, they can be used to glimpse a less evolved world of ancient continents and vanished oceans. Erudite and entertaining, this book is a uniquely exuberant homage to a fabulously singular species.
were the first known animals to live symbiotically with sulphur bacteria. The Utica Shale was not unique in its exquisite preservation of trilobite limbs. In Germany, to either side of the River Mosel and in the adjacent parts of the Rhineland, another dark slate comes to the surface. The Hunsrück Slate has been used for roofing since medieval times, and by the middle years of the nineteenth century there were many productive quarries. Even today, an open cast working at Bundenbach still employs
four”… and so on to a hundred or two. The trouble was that you had only to look away for an instant, or sneeze, to forget exactly where you were, so it was back again to “one, two, three …”Teeth were gnashed, imprecations muttered, deities’ names taken in vain. Eventually I hit upon the notion of pricking each counted lens on the photograph with a pin, so that it wasn’t counted twice. The trouble was moving to the next photograph: what was the last lens that I’d identified and how did they link
recently, a late Precambrian animal embryo was discovered in China, amazingly preserved cell by cell in the mineral calcium phosphate; age by itself is evidently no proof against miracles. It would be wonderful to amaze the world with proof of the missing stages of evolution, tiny animals that set the designs for the future of life. Somewhere, there should be a small trilobite, an animal with the potential for spinning an almost endless variety of costumes for three hundred million years. The
to one shore of this seaway that Hardy’s trilobite lived (had it not been fiction) and Cornwall’s twisted cliffs and noble granites were the legacy of the ultimate demise of that ocean in the next great tectonic cycle. Earth, like a nagging conscience, reopens old wounds. Who knows if some tens of millions of years hence Asia may again cleave apart along the Urals? Who knows if new animals may yet evolve at the bidding of a shattered homeland? Ordovician Gondwana from a polar projection,
based on finding transitional sequences to a known species. I was lucky enough to find some wonderful protaspides from the Ordovician rocks of Spitsbergen, which are shown in the figure. These were preserved in calcium phosphate, which replaced the original thin calcareous shells, and so perfect was the replication that tiny spines a few thousandths of a millimetre across are faithfully recorded; just because something is small does not mean it is featureless. Among this cornucopia of microscopic