The tetrapod microbiota of the Wessex Formation (Lower Cretaceous, Barremian) of the Isle of Wight, UK

Although remains of small vertebrates in the (Barremian) Wessex Formation of the Isle of Wight, southern England, are rare and fragmentary bulk screening techniques have resulted in the recoveryof a diverse terrestrial microvertebrate fauna including lissamphibians, archosaurs, lepidosaurs, andmammals. Most taxa are generically distinct from those occurring in other European Early Cretaceousdeposits, but in general aspect the faunas are similar. Palaeoenvironmental differences appear to haveaffected the balance of taxa present but the faunas are dominated by an essentially relictual assemblage of small theropod and ornithischian dinosaurs, crocodilians, scincomorph and anguimorph lizards, frogs of discoglossid grade, salamanders and albanerpetontids. Many elements of this fauna are also encountered inthe Early Cretaceous of central and eastern Asia, northern Gondwana and North America. It is becomingincreasingly apparent that despite evidence for the existence of marine barriers separating these areas,faunal interchange occurred. The Wessex Formation microbiota lends further support to this concept andthe occurrence of a gobiconodontid and a spalacolestine spalacotheriid in particular are consistent withother evidence supporting east/west, west/east dispersals.