Includes index.

Bibliography: p. 325-335.

CONTENTS:
A prologue in pictures
-- The ladder and the cone : iconographies of progress -- Replaying life's tape : the crucial experiment -- Inset : the meanings of diversity and disparity -- Life before the Burgess : the Cambrian explosion and the origin of animals -- Life after the Burgess : soft-bodied faunas as windows into the past -- The setting of the Burgess Shale -- A quiet revolution -- A methodology of research -- The chronology of a transformation -- Inset : taxonomy and the status of phyla -- Inset : the classification and anatomy of arthropods -- Act 1. Marrella and Yohoia : the dawning and consolidation of suspicion, 1971 - 1974 -- Act 2. A new view takes hold : homage to opabinia, 1975 -- Act 3. The revision expands : the success of a research team, 1975 - 1978 -- Completion and codification of an argument : naraoia and aysheaia, 1977 - 1978 -- Act 5. The maturation of a research program : life after aysheaia, 1979 - doomsday (there are no final answers) -- Coda -- Summary statement on the bestiary of the Burgess Shale -- The Burgess Shale as a Cambrian generality -- The two great problems of the Burgess Shale -- The basis for Walcott’s allegiance to the cone of diversity -- The Burgess Shale and the nature of history -- Inset : a plea for the high status of natural history -- A story of alternatives -- General patterns that illustrate contingency -- Seven possible worlds -- An epilogue on PIKAIA.