The current volume of the mammalian handbook has rather diversified composition from the systematic point of view that includes representatives of three major lineages (superorders) of placental mammals. The volume covers two orders of Xenathra and five orders of smaller species formerly classified in the traditional taxon of Insectivora. Xenarthrans are currently considered as one of the basal lineages of placentals, whereas the Insectivora were decisively shown to represent a polyphyletic unit which should be divided into several separate taxa showing various convergent features. The present volume appears therefore rather heterogeneous in respect of selection of the taxa included, however, some of the most notable mammals are depicted and described.
Various groups included in the present volume are just relic remnants of the past species richness and morphological diversity. Armadillos belonging to the order Cingulata are represented by two extant families, and remarkable extinct groups such as glyptodonts might be closely related to certain living lineages. The fossil diversity was much greater compared to the extant biota also in sloths and anteaters included in the order Pilosa. Both sloths and anteaters are classified in two extant families, respectively, and the relationships of the living species with their extinct relatives are investigated using ancient DNA analyses. Small insectivores native to Africa are represented by the orders Afrosoricida and Macroscelidea, both belonging to another basal lineage of placental mammals, Afrotheria. Afrosoricida have experienced remarkable convergent evolution with hedgehogs, shrews and moles, and three families are recognized now within the order. The history of Madagascar colonization by tenrecs is still one of the most exciting events on mammalian phylogeny. Sengis (Macroscelidea, previously called elephant shrews) are the other order of small insectivorous afrotherian mammals.
Other two orders included in this volume belong to the superorder of Euarchontoglires, and they were formerly associated with insectivorous or other placental lineages. The tree shrews (Scandentia) are typical living fossils, and currently recognized in two extant families. The systematic position of tree shrews is still hotly debated. Gliding colugos (Dermoptera) were assumed to be related either to bats or to primates, and the latter option is probably correct. Only single family of colugos is currently recognized but it may include a number of cryptic species.
The other insectivorous placentals are now included in the order Eulipotyphla belonging to the superorder of Laurasiatheria. The traditional members of this order are the families of hedgehogs, shrews and moles. The position of enigmatic solenodons from the Caribbean islands has been intensively studied, and it seems that they represent a basal and ancient branch of the Eulipotyphla.
Altogether, 36 authors participated in setting up of the volume. The book is introduced by a chapter dealing with conservation priorities and actions carried out in individual taxa included. The systematic part of the book follows the standard arrangement used in the previous volumes. A detailed description of various important aspects of life history is given for each group and the text is accompanied by superb illustrations, photos and distribution maps.
This volume is a unique and essential source of information for any reader interested in the life of mammals. The last volume of this series will be devoted to bats (Chiroptera) and its publication is expected in the next year.
