Fossil and Recent Sponges contains articles on taxonomic, phylogenetic and ecological aspects of sponges of both biological and paleontological interest. They focus on three main topics: phylogeny and systematics, biology, and paleoecology of sponges. The reader is offered an overview over the most important aspects of current sponge research: - establishment of a new taxonomy based on mono phyletic groups (phylogenetic systematics) including recent and fossil taxa - new concepts of the biomineralisation of sponge skeletons - palaeoenvironmental analysis of fossil sponge buildups.
The publication of this book was undertaken with two purposes in view: to bring together informatian on the deposition by living organ isms of unique skeletal structures composed of amorphous silica, and to review recent data on the involvement of silicon in physiological and biochemical processes. Although widely varying viewpoints are represented, all the contributors are very interested in the events in volved in the formatian of siliceaus structures and their function. Data presented deal with these questions in a variety of plant and animal systems, and at levels ranging from the evolutionary to the biochemical and ultrastructural. Innovations in electron microscopy and, indeed, the advent of electron microscopy itself, have stimulated many ultra structural studies of silica deposition, work which has deepened and widened the interest in those organisms which routinely produce "glassy skeletons. " The question of how silicon participates in biological systems in volves a spectrum of fields that indudes the chemistry of silicon per se, its biogeochemistry, biochemistry, ecology, and so forth. In this book, however, attention is focused up on the biological aspects of silicon and siliceous structures, with emphasis on the evolutian, phylogeny, morphology, and distribution of siliceaus structures, on the cellular as peets of silica deposition, and on the physiological and biochemical roles of silicon. This volume represents the first compilatian of such data. Because such a variety of subjects and fields are covered, the reader will have to glean for himself some of the comparative aspects of the data.
Research whilst compiling this book has uncovered a fauna about twice the size as that previously published in the literature and consequently Systema Porifera revises and stabilizes the systematics of the phylum to accommodate this new knowledge in a contemporary framework. Practical tools (key illustrations, descriptions of character) are provided to facilitate the assignment of approximately 680 extant and 100 fossil genera. Systema Porifera is unique making sponge taxonomy widely available at the practical level of classification (genera, families, order). It is a taxonomic revision of sponges and spongiomorphis (such as sphinctozoans and archaeocyathans) based on re-evaluation of type materials and evidence. It is also a practical guide to sponge identification providing descriptions and illustrations of characters and interpretation of their importance to systematics. Systema Porifera addresses many long standing nomenclatural problems and provides a sound baseline for future debate on sponges and their place in time and space. Systema Porifera describes 3 classes, 7 subclasses, 24 orders, 127 families and 682 valid genera of extant sponges (with over 1600 nominal generic names and an additional 500 invalid names treated). Treatment of the fossil fauna is less comprehensive or critical, although 6 classes, 30 orders, 245 families and 998 fossil genera are mentioned. Keys to all recent and many fossil taxa are provided.
