If ever there was a confusing title for the proceedings of a congress, this must be it. This issue of the South African journal African Invertebrates: a Journal of Biodiversity Research, formerly the Annals of the Natal Museum, is devoted to a congress held in Pretoria in February 2005 which was entitled ‘Fossils X3’. It was actually the Third International Congress of Palaeoentomology, the Second International Meeting on Palaeoarthropodology and the Second World Congress on Amber and its Inclusions, which is presumably why the organizers struggled to find an all-inclusive and brief title, ‘Fossils X3’ – but the vital clue to its subject matter is encapsulated in the subtitle ‘Insects. Arthropods. Amber’, which does not appear on the cover of this volume.

So ‘Fossils X3’ is actually a collection of some 18 refereed papers, published effectively as the proceedings of that Congress. They are grouped into three sections on Palaeoecology and Taphonomy; Taxonomy and Phylogeny; and Amber Studies. Altogether, five of the contributions are amber-based studies and three of these focus on Early Cretaceous amber especially from Lebanon. At some 125 million years old, this amber, like many other fossil resins, provides astonishingly detailed insights to the entomofauna of the time. The growing realization that old amber, like this Cretaceous material, can still be found promises an important complement to other more widespread sediment-based entomofaunas.

However, classic sediment-based entomofaunas, such as those of the Eocene age Lake Messel in Germany, can still provide interesting and important ecological insights. In one contribution, Wedmann & Richter have been able to trace an aquatic food web from Messel from the analysis of the abundant coprolites from small fish. This source has provided the larvae and pupae of phantom midges (chaorbids) and from this the authors provide an outline of the major role played by large chaorbid populations in the pelagic system of the lake.