Trilobites of New York by Thomas Whiteley, Gerald Kloc and Carlton Brett, Cornell University Press, $55, ISBN 0801439698 Reviewed by Richard Fortey
ONCE amazingly abundant and varied, trilobites have been described as 鈥渢he beetles of the Palaeozoic鈥�. They swarmed in their millions in and round the seas of the early Cambrian, 545 million years ago, to the end of the Permian, when they became extinct, occupying many of the ecological niches now taken by crustaceans. The world was all the poorer for their passing.
For the past 150 years, one of the great hot spots for trilobite fossils has been New York state. Several pioneering palaeontologists, among them James Hall, first publicised the fossil treasures from upstate limestones and shales. And it was here that the delicate limbs of fossilised trilobites were first discovered. In Trilobites of New York, Thomas Whiteley, Gerald Kloc and Carlton Brett have compiled a splendid photographic tribute to the area鈥檚 trilobites.
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What is it that鈥檚 so fascinating about trilobites? Their variety, for one thing: they range from predators nearly a metre long to small filter feeders and sediment grazers. They are remarkable, too, having compound eyes made of calcite crystals, a structure virtually unique in the animal kingdom. It may be their prominent eyes made of hundreds of lenses that makes them particularly appealing to collectors, but their range of fantastic shapes also has an aesthetic interest. Fortunately, trilobites had a tough upper carapace of calcium carbonate, so well-preserved fossils of these intriguing arthropods are comparatively common. They can be found on sale for a few pounds in rock shops, most of them from Morocco, where mining trilobites has become big business. Among fossil lovers, they are diminutive rivals for dinosaurs.
Trilobites of New York showcases fossils from the famous limestones of the Ordovician Trenton Group, or the Devonian Hamilton group. Here we meet the phacopid trilobites, with their sophisticated biconvex eye lenses and knobbly skeletons preserved down to the last pimple. Some sport spiny tails like combs, others are smooth, with their eyes elevated on stalks. There are the mysterious trinucleids with heads surrounded by a kind of colander, a pitted fringe whose purpose still defies scientific explanation. A picture gallery goes a long way towards dispelling notions that the Palaeozoic sea floor might have been a monotonous place compared with today鈥檚.
Gratifying though it is to have a coffee-table book of trilobites, is rather more than that. It has a good introduction to the rocks and stratigraphy of New York 鈥� an excellent way of putting the creatures into context. With this book in the car, you could tour the state and start your own collection. There is a handy summary of trilobite classification, and thumbnail descriptions of the species illustrated. I have only one criticism: the Cambrian animals get rather short shrift. Otherwise, you can鈥檛 buy a better introduction to one of the most fascinating groups of marine animals. It is just too bad that one of their kind did not linger on to the present, like its distant relative, the horseshoe crab.