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出版Boydell Press, 1992
主題Science / General
ISBN08511531199780851153117
URLhttp://books.google.com.hk/books?id=LIxwQgAACAAJ&hl=&source=gbs_api
註釋Trilobites lived for over 300 million years in the seas of the world, and the remains of their hard parts have long attracted collectors. This new, definitive study - plates and text in equal measure - focuses on kinds of trilobites from rocks of all the Palaeozoic periods in a series of more than 120 first-class photographs, with complementary text. These include rare specimens which have preserved soft parts such as antennae and limbs; from these the anatomy may be reconstructed, and one may speculate on the way trilobites behaved. The calcified trilobite shell was outside the body, hence had to be cast at intervals as the animal grew. Specimens from these intervals show how the trilobite changed in form as it grew from a tiny early stage to a length of several centimetres. The great succession of kinds of trilobites evolved in a world of changing geography and climate. How trilobites were preserved, the kinds of rocks in which they occur, and traces of their activity, are described in order to infer where they lived in ancient seas and their manner of life. Some kinds were world-wide in distribution, others limited to seas of differing depth or temperature. This record in the rocks of different continents shows that new kinds arose to replace extinct forms, in many cases abruptly, and that particular trends of change occurred repeatedly. Mechanisms which may have effected these changes are discussed. The long-continued search for evolutionary links between kinds of trilobites, as the basis for a natural classification, is reviewed in the light of conflicting contemporary ideas.