In spite of its relatively small land area, the island of Great Britain possesses an exceptionally varied suite of rocks, minerals and fossils ranging in age from the Archaean to the Pleistocene. These deposits were crucial for early geologists and palaeontologists as they struggled to develop theories relating to the concepts of deep time, earth structure, the operation of surface processes and the evolution of life. As a result, work on this insignificant lump of land has been of lasting global significance. However, many of the sites that yielded (and in many cases continue to yield) these insights are under threat from development. In order to meet this threat, a review of important geological sites was commissioned in the late 1970s to document localities of particular significance and to build cases for their future preservation.
This volume is the thirty-second to appear in the ensuing Geological Conservation Review Series and deals with a small, but exceptionally important, part of Great Britain's palaeontological heritage: its record of Mesozoic and Tertiary birds and mammals. In many ways, this can be viewed as a companion to the earlier tome on fossil reptiles (Benton & Spencer, Reference Benton and Spencer1995). Inevitably, these two books have a great deal in common, as some significant reptile-bearing sites have also yielded other notable vertebrate material. The authors propose 26 field sites for consideration by the Geological Conservation Review (GCR), with the hope that they can be preserved for future study and reference. Ten of these sites are noted for Mesozoic mammals; eight for Tertiary mammals; and eight for Tertiary birds. However, due to the overlap between this volume and the fossil reptile volume, only 15 of these sites are actually ‘new’ GCR recommendations. Moreover, as the Tertiary mammals and birds are dealt with in separate chapters, there is considerable overlap within the book itself: three of the mammal–bird sites appear twice within this volume. With the benefit of hindsight, it may have been better to combine the reptile and mammal–bird volumes into a single title: once all of the repetitive sections on site descriptions and stratigraphy had been removed, the additional text pertaining solely to mammal and bird localities would have been relatively short. Nevertheless, the authors have been able to take advantage of this situation, as it has enabled them to update and correct some of the information published in the earlier reptile compilation.
Unless you are a palaeomammalogist it is easy to forget that Great Britain has one of the richest records of Mesozoic mammals from anywhere in the world, a record that encompasses the Late Triassic to the Early Cretaceous. Similarly, the Eocene and Oligocene deposits of southern England have yielded a rich diversity of mammals and birds. Although the authors are right to dismiss the majority of putative bird specimens from the British Mesozoic, it was slightly surprising that they were so dismissive of the Early Cretaceous taxon Enaliornis from the Cambridge Greensand, which is represented by three-dimensional skull material as well as limb bones: it is currently one of the very few Cretaceous birds known from Europe. This omission aside, the authors present a useful overview of all of the sites mentioned, incorporating faunal lists, history of research and stratigraphical logs, as well as assessments of each site's regional and (in many cases) international importance. All of this forms a very accessible summary of the extensive literature that now exists on these animals and provides a set of concise introductions to particular localities that will be of interest to researchers working on these, and other, groups. It is to be hoped that all of the evidence marshalled by the authors will convince policymakers of the need to conserve and protect these valuable sites.
