The palaeoenvironment associated with a partial Iguanodon skeleton from the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks (Ockley, Surrey, UK), based on palynomorphs and ostracods Eleanor Nye a , Susanne Feist-Burkhardt a, * , David J. Horne b,c , Andrew J. Ross a , John E. Whittaker a a Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK b Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK c Department of Geography, Queen Mary, University of London, Mile End Road, London E1 4NS, UK Received 20 June 2007; accepted in revised form 8 January 2008 Available online 6 February 2008 Abstract In 2001 a partial skeleton of an Iguanodon was discovered in the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brick- works near Ockley, Surrey, UK. When the dinosaur was excavated, a detailed stratigraphic section was logged and 25 samples taken for paly- nological and micropalaeontological (ostracod and megaspore) analysis, including a detailed sample set of the dinosaur bed itself. Qualitative and quantitative analysis of the palynoflora revealed rich and well-preserved non-marine assemblages of pollen and spores, including early an- giosperms, and freshwater green algae. Four types of angiosperm pollen are described and assigned to the genus Retimonocolpites Pierce, 1961, but left in open nomenclature. Some marine elements such as dinoflagellate cysts are identified as the result of reworking of Middle and Upper Jurassic sediments. The pollen/spore assemblages depict a vegetational change from principally gymnosperm-dominated assemblages at the base to principally pteridophyte-dominated assemblages at the top of the section. The dinosaur bed shows a pteridophyte-dominated assemblage, with a significantly high amount of the freshwater green alga Scenedesmus novilunaris He Cheng-quan et al., 1992. Samples close to the dinosaur bed yielded the first useful ostracod finds from Smokejacks Brickworks: well-preserved assemblages containing Cypridea clavata (Anderson, 1939), Damonella cf. pygmaea (Anderson, 1941), Stenestroemia cf. cressida Anderson, 1971 and Stenestroemia sp. A, and fragments and damaged valves of a thin-shelled ostracod, possibly belonging to Mantelliana Anderson, 1966. Those identified as Cypridea clavata show a wide range of morphological variety and in opposition to Anderson’s (1967, 1985) taxonomic scheme, which would assign them to up to five different taxa, they are considered to be intraspecific variants of a single species. The possibilities and limitations of age determination of the Wealden sediments using palynomorphs and ostracods are discussed; distinct forms of early angiosperm pollen, together with the ostracod fauna, are consistent with an early Barremian age. Pollen and spores are discussed in terms of their parent plants and the reconstruction of vegetation and palaeoclimate. Palynology and ostracods give evidence for temporary freshwater conditions at the time when the Iguanodon died and the carcase was buried. Ó 2008 The Natural History Museum. Published by Elsevier Ltd. All rights reserved. Keywords: Lower Cretaceous; Wealden; England; Palynology; Ostracods; Megaspores; Iguanodon; Palaeoenvironment; Palaeoclimate; Preservation 1. Introduction The sediments exposed at Smokejacks Brickworks near Ockley, Surrey, UK (Fig. 1), have long been of interest due to the occurrence of fossil vertebrate remains, most famously the 1983 discovery of the fish-eating theropod dinosaur Baryo- nyx walkeri, described by Charig and Milner (1997). On 22nd July 2001 a partial skeleton of the dinosaur Iguanodon ather- fieldensis Hooley, 1925 was discovered by Mr Geoff Toye on a Geologists’ Association field trip (Austen, 2001). That summer a team from the Natural History Museum, London, * Corresponding author. E-mail address: s.feist-burkhardt@nhm.ac.uk (S. Feist-Burkhardt). 0195-6671/$ - see front matter Ó 2008 The Natural History Museum. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2008.01.004 Cretaceous Research 29 (2008) 417e444 www.elsevier.com/locate/CretRes