Herpetofauna of the Ipswichian Interglacial Bed (Late Pleistocene) of the Itteringham Gravel Pit, Norfolk, England

Abstract

-At least four species of anurans, one tortoise and one snake were identified from the Ipswichian interglacial bed (Late Pleistocene) of the Itteringham Gravel Pit, Norfolk, England. A tree frog (Hyla sp.) is reported for the first time as a British fossil. The herpetofauna indicates that the major habitat was a lentic one. The occurrence of the tree frog (Hyla sp.), continental water frogs (Rana), and the European pond tortoise (Emys orbicularis) indicates a continental climate with warmer summers than occur in England today. The mammalian fauna of the British Pleistocene has been well-studied (Stuart, 1982), but the British Pleistocene herpetofauna has been largely neglected until recently. These recent works include reports of the European pond tortoise from interglacial sites (Stuart, 1979, 1982), and short herpetofaunal papers on Cromerian (Holman, 1987c; Holman et al., 1988), Hoxnian (Holman, 1987a), Ipswichian (Holman, 1987b), Devensian/Flandrian (Holman, 1988) and Flandrian (Holman, 1985, 1987a) localities. Studies of fossil herpetofaunas are important in making paleoecological interpretations, for modern amphibians and reptiles have specific ecological requirements and most Pleistocene species have modern equivalents that have been well-studied in Britain and on the continent. Moreover, certain species may be particularly important in indicating specific environmental conditions because of stringent climatic reproductive constraints (Stuart, 1979). The Ipswichian Interglacial Stage.-Except for the Flandrian, the Ipswichian is the best known of the British interglacials. The Ipswichian (ca. 120,000-110,000 years before present) occurs between the cold glacial times of the older Wolstonian stage and the younger Devensian stage. Stuart (1982) provides a general discussion of the most important Ipswichian sites and their vertebrate fauna. The presence of fossils of the African hippo (Hippopotamus amphibius) is generally accepted as diagnostic of the Ipswichian. Some other mammals which no longer are native to Britain but do appear in the Ipswichian are the horse (Equus ferus), spotted hyena (Crocuta crocuta) and the lion (Panthera leo). The Ipswichian has also yielded the European pond tortoise (Emys orbicularis) from many of its sites. The type site of the Ipswichian is Bobbitshole, Ipswich, England. The Itteringham Deposit.-The Itteringham Gravel Pit (National Grid Reference 139305) is located beside the River Bure in the parish of Oulton, 6 km west of Aylsham, Norfolk, England. Deposits belonging to four distinct climatic stages have been identified. The uppermost valley deposits (mostly peat) belong to the present (Flandrian) interglacial. Beneath these are gravels and clays with fossil and sedimentary indications of intense cold and these are assigned to the last (Devensian) glacial. Stratigraphically lower are detrital muds and organic sands which are fully interglacial in character. 33 This content downloaded from 207.46.13.167 on Thu, 21 Jul 2016 05:09:32 UTC All use subject to http://about.jstor.org/terms L. A. HALLOCK ET AL.