A small fauna of vertebrates is recorded from the Insect Limestone, Bembridge Marls Member, Bouldnor Formation, late Priabonian, latest Eocene, of the Isle of Wight, UK. The taxa represented are unidentified teleost fishes, lizards including a scincoid, unidentified birds and the theridomyid rodent Isoptychus. The scincoid represents the youngest record of the group in the UK. Of particular note is the taphonomic interpretation based on the preservation of anatomical parts of land-based tetrapods that would have been most likely transported to the site of deposition by wind, namely bird feathers and pieces of shed lizard skin. These comprise the majority of the specimens and suggest that the dominant transport mechanism was wind.

The Insect Limestone has long been known as a source of exquisitely preserved insects and other arthropods. It occurs on the north side of the Isle of Wight and is latest Eocene in age. A summary of the history of the study of the Insect Limestone is given, along with detailed stratigraphical and sedimentological information. This paper is the first in a thematic set of papers.

The types and undescribed material of the hymenopteran fossils of the Insect Bed of the Bembridge Marls from the Isle of Wight (UK) are critically revised and studied. A total of 1460 fossils are recorded and attributed to 20 families: Gasteruptiidae s.l. (1); Proctotrupidae (3); Diapriidae (24); Cynipidae (7); Figitidae (6); Pteromalidae (1); Agaonidae (3); Scelionidae (12); Platygastridae (2); Ichneumonidae (32); Braconidae (75); Bethylidae (3); Crabronidae (2); Sphecidae (1); Apidae (2); Scoliidae (1); Tiphiidae (2); Vespidae (4); and Formicidae (1220). Described as new are 51 species, 13 genera, two tribes and two subfamilies. Minimum number of species recorded (either as described species or representing higher taxa with no described species in the assemblage) is 118. The composition of the hymenopteran assemblage is most similar to that of Baltic amber and indicative of a well forested territory, as well as of a humid, equable (aseasonal but not very hot) climate, more typically equable than in the Baltic amber source area, judging from the absence of Aphidiinae and scarcity of aphids.