Two fleas have been collected in association with abundant remains of fish, plants, phyllopod Crustacea (Conchostraca, Anostraca and Cladocera) and other insects in a Lower Cretaceous siltstone at Koonwarra, southern Gippsland, Australia. The insect fauna consists mainly of the aquatic immature stages of Ephemeroptera (mayflies), Diptera (midges), Coleoptera (beetles), Plecoptera (stoneflies) and Odonata (dragonflies and damselflies). The aquatic larvae of the scorpionfly family Nannochoristidae (Mecoptera) are also preserved. There is also a small adventitious fauna of adult insects, including the fleas, the immature stages of which are not aquatic. The only known remains of warm-blooded vertebrates are feathers1.