Jennifer Clack’s new book Gaining Ground – The Origin and Evolution of

Tetrapods, a recent addition to the grow-ing list of paleontological titles from Indi-ana University Press, comes along at an opportune moment for students of verte-brate evolution, in particular those with a serious academic interest in the early fos-sil record of tetrapods and their piscine rel-atives. Clack has been at the forefront during the recent dynamic period of research on this topic, contributing in areas ranging from how many toes the earliest tetrapods had, to basal tetrapod interrelationships and lifestyles. Gaining Ground is a timely, well-written, and com-prehensive synthesis, and it is nice to read a single-authored work for a change, rather than yet another multi-authored symposium volume. The emphasis is on major morphological transitions in the early fossil record of tetrapods, which is Clack’s specialty, but the book also incor-porates new data from genetics and devel-opmental biology that bear on the group’s history. The strong treatment of Devonian tetrapods is particularly noteworthy, and especially appropriate in that the number of Devonian tetrapod genera has risen from two or three to eight over the last couple of decades, and the story has expanded geographi-cally from East Greenland, for many years the only ‘home’ for Devonian tetra-pods, to include recent finds from North America, the Baltic region, an