A new large basal tetanuran (Dinosauria: Theropoda) from the Wessex Formation (Barremian) of the Isle Of Wight, England

The Wessex Formation of the Isle of Wight, southern England, has yielded one of the most diverse Early Cretaceous dinosaur assemblages in the world. While isolated theropod remains have been known from the Wessex Formation since the 1860s (Fox in Anon., 1866), it is only recently that associated specimens, and remains representing large-bodied taxa, have been described in the literature. Foremost among these is the allosauroid Neovenator salerii, which is represented by approximately 70% of the skeleton, making it the most complete large theropod known from Europe (Hutt et al., 1996; Naish et al., 2001; Brusatte et al., in press). Other large-bodied theropods from the Wessex Formation include the spinosauroid Baryonyx,which is represented by isolated teeth and vertebrae (Martill and Hutt, 1996; Hutt and Newbery, 2004; Naish and Martill, 2007), and the basal tyrannosauroid Eotyrannus lengi, which is known from an associated specimen and referred material that indicates some individuals obtained large size (Hutt et al., 2001; Naish, 2006). Other Wessex Formation theropod remains pertain to mostly small-bodied coelurosaurs, and include the enigmatic taxa Aristosuchus pusillus, Calamosaurus foxi, Ornithodesmus cluniculus, and Thecocoelurus daviesi (Naish et al., 2001), as well as isolated teeth that have been interpreted as belonging to dromaeosaurids (Sweetman, 2004). Two large-bodied theropod taxa, Becklespinax altispinax and Valdoraptor oweni, are known from the Hastings Beds Group, of somewhat older age than the Wessex Formation (Berriasian-Valanginian; Naish and Martill, 2007). Here we report remains collected by Keith Simmonds of Brighstone from Chilton Chine, Brighstone Bay, Isle of Wight in 1986, that represent an additional large-bodied Wessex Formation theropod (MIWG 6350). Although briefly listed as Theropoda indet. in a table of specimens published by Hutt (2001), MIWG 6350 has not yet been described in the literature. While this material is highly incomplete, it can be compared with contemporaneous theropods from the Wessex Formation and other Lower Cretaceous units worldwide. It is significant in indicating the presence of a hitherto unrecognized large-bodied theropod from the Wessex Formation. This demonstrates that at least three large-bodied predators were present in theropod faunas of the Barremian of the United Kingdom.