This volume of the Handbook of Zoology summarizes "small" groups of animals across the animal kingdom. Dicyemida and Orthonectida are enigmatic parasites, formerly united as "Mesozoa" and their position among the multicellular animals is still not known with certainty. Placozoa are small, flat marine animals which provide important information on metazoan evolution. Comb jellies (Ctenophora) are esthetically fascinating animals which cause considerable discussion about their phylogenetic position. Seisonida are closely related to rotifers and acanthocephalans. Cycliophora were discovered and described as one of the last higher taxa and surprise by their complex life cycle. Kamptozoa (= Entoprocta) are small sessile animals in the sea and sometimes also in freshwater. Arrow worms (Chaetognatha) play an important role as predators in the plankton, but they also include benthic forms. Pterobranchia and acorn worms (Enteropneusta) belong to the deuterostomia and are related to echinoderms. In particular enteropneusts play an important role in understanding deuterostome evolution. These chapters provide up to date reviews of these exiting groups with reference to the important literature and therefore serves as an important source of information.

This book is the first in a series of 4 volumes in the Handbook of Zoology series about morphology, anatomy, reproduction, development, ecology, phylogeny and systematics of Annelida. This first volume covers members of the so-called basal radiation and the first part of Sedentaria. It is supplemented by chapters on the history of annelid research, their fossil record, and an introduction to the phylogeny of annelids and their position in the tree of life. In the latter chapter the history of their systematic is reviewed giving an almost complete picture of systematic-scientific progress especially in the past years which changed our view on annelid phylogeny dramatically. The most basal annelids, lately united as Palaeoannelida, represent two families of aberrant polychaetes formerly often suggested to be highly derived which now give us a fresh look on how the ancestral annelid may have looked like. These lack certain key characters such as nuchal organs and possess rather simple nervous systems which now likely represent primitive character states. In this basal radiation the first taxon of apparently unsegmented and achaetigerous animals is positioned, the Sipuncula. Most likely another group of platyhelminth-like and unsegmented and even chaeta-lees annelids, Lobatocerebridae falls into this basal radiation. The section of Sedentaria starts with Orbiniida, a taxon characterized by elongated, thread-like worms which do not have anterior appendages like palps and comprises several families representing members of the Meiofauna. These minute worms often inhabiting the interstitial spaces in marine sands are suggested to have evolved by progenesis. The second higher taxon is represented by Cirratuliformia comprising nine families of typical sedentary polychaetes each of which showing a remarkable variation of the annelid body plan. Members of this taxon usually exhibit many annelid characters but certain also lack the most typical prostomial appendages, the palps.

This book is the first of four volumes in the Handbook of Zoology series which treat the systematics and biology of Coleoptera. With approximately 350,000 described species, Coleoptera are by far the most species-rich order of insects and the largest group of animals of comparable geological age. The beetle volumes will meet the demand of modern biologists seeking to answer questions about Coleoptera phylogeny, evolution, and ecology. This first Coleoptera volume covers the suborders Archostemata, Myxophaga and Adephaga, and the basal series of Polyphaga, with information on world distribution, biology, morphology of all life stages (including anatomy), phylogeny and comments on taxonomy.

There are nearly 6,000 mammalian species, among them our own. Research on our evolutionary cousins has a long history, but the last 20 years have seen particularly rapid progress in disentangling the interrelationships and evolutionary history of mammals. The present volume combines up-to-date reviews on mammalian phylogenetics with paleontological, taxonomic and evolutionary chapters and also summarizes the historical development of our insights in mammalian relationships, and thus our own place in the Tree of Life. Our book places the present biodiversity crisis in context, with one in four mammal species threatened by extinction, and reviews the distribution and conservation of mammalian diversity across the globe. This volume is the introductory tome to the new Mammalia series of the Handbook of Zoology and will be essential reading for mammalogists, zoologists and conservationists alike.