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Phosphatic remains (tooth enamel, turtle shell fragments and fish scales) of continental vertebrates (freshwater fish, crocodilians, turtles, and theropod and sauropod dinosaurs) recovered from eight localities of NE Thailand ranging in age from the Late Jurassic to the late Early Cretac- eous have been analysed for their oxygen isotopic compositions (d 18 Op). From these preliminary data, local meteoric water d 18 Ow values estimated using d 18 Op values of crocodilians and turtles range from 24.1+ 2‰ at the end of the Jurassic to 28.3+ 2‰ during the Early Cretaceous, suggesting a transition from dry to wetter climates with increasing amount of seasonal precipitation from several hundred millimetres per year to several thousand millimetres. Measurable offsets in d 18 Op values observed between dinosaur taxa (the spinosaurid theropod Siamosaurus, other ther- opods and nemegtosaurid sauropods) are interpreted in terms of differences in water strategies, and suggest that Siamosaurus had habits similar to those of semi-aquatic vertebrates such as crocodi- lians or freshwater turtles.

A new skeleton of a sauropod dinosaur has been discovered in the Early Cretaceous Sao Khua Formation at Ban Na Khrai in Changwat Kalasin (NE Thailand). All sauropod bones from Ban Na Khrai share all their characteristics with the type specimen of Phuwiangosaurus sirindhornae Martin, Buffetaut & Suteethorn 1994. The 60% complete skeleton is very well preserved and includes cranial elements (a tooth, a frontal, a postorbital, a squamosal, both quadrates, and the braincase), whereas the type specimen is only 10% complete and consists of postcranial bones only. The material from Ban Na Khrai belongs to a single subadult individual of Phuwiangosaurus , as attested by the unfused neurocentral sutures of the vertebrae, which are firmly fused and larger in size in the holotypic specimen.

Over the last 25 years, rich vertebrate assemblages have been discovered in three distinct formations of the Late Jurassic and Early Cretaceous of Thailand. This work aims to compare the taxonomic assemblages of SE Asia within their palaeogeographical context in Asia. Occurrences of 477 taxa in 94 Regional Faunal Assemblages (RFA) have provided the rawmaterialforproducinga dissimilaritymatrixbasedontheRaup& Crickindex.Thesedistances havebeeninvestigated statistically toinferrelationships betweenthediverse faunalassemblagesin space andtime. Ourresultsshowthat theThai formations are moresimilartoeach otherthan toany other formations, suggesting a strong provincialism. The relationship of SE Asian RFAs with other Asian RFAs is more influenced by the presence of freshwater or near-shore taxa than by strictly terrestrial ones. Our analysis shows that the faunal interchange between RFAs was rather low from the Late Jurassic to the end of the Early Cretaceous. However, faunal dispersals dramatically decreased during the mid-Early Cretaceous in Asia. The faunas show an overall stronger provin- cialism during the mid-Early Cretaceous, indicating the role of possible geographical barriers. This event is characterized by the absence of ornithischian dinosaurs in the Sao Khua Formation although they are present in the under- and overlying formations. Taxonomic diversity and exchanges between faunal assemblages recovered rapidly as early as the Aptian in Asia, but the fauna of SE Asia still retained a strong biogeographical signature.

Postcranial remains of a small theropod dinosaur, including vertebrae, incomplete pubes, tibiae, an incomplete fibula, metatarsals and phalanges, from the Early Cretaceous Sao Khua Formation of Phu Wiang, Khon Kaen Province, NE Thailand, are described as a new taxonofornithomimosaur, Kinnareemimus khonkaenensis,gen.etsp.nov.Thisearly'ostrichdino- saur' is characterized by a fairly advancedmetatarsus, in which metatarsal III, although still visible proximally between metatarsals II and IV in cranial view, is markedly 'pinched' more distally and becomes triangular in cross-section. The condition of its metatarsus shows that Kinnareemimus khonkaenensis is more derived than the geologically younger primitive ornithomimosaurs Harpy- mimus and Garudimimus, but less derived than Archaeornithomimus. Its occurrence in the Early Cretaceous of Thailand suggests that advanced ornithomimosaurs may have originated in Asia.

RICHARD T. J. MOODY1*, ERIC BUFFETAUT2, DARREN NAISH3 & DAVID M. MARTILL3 Faculty of Science, Kingston University, Penrhyn Road, Kingston KT1 2EE, UK Centre National de la Recherche Scientifique, UMR 8538, Laboratoire de Geologie de l’Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris Cedex 05, France School of Earth & Environmental Sciences, Burnaby Building, Burnaby Road, University of Portsmouth, Portsmouth PO1 3QL, UK

Pterosaurs were a peculiar group of Mesozoic vertebrates, which acquired the ability to fly in an original way, using a membrane attached to a single finger of the hand. Ever since the first description of a pterosaur skeleton in 1784, these remarkable animals have elicited much discussion and controversy among palaeontologists, and many basic questions about their origin, evolution and biology remain disputed. In the last few years, interest in pterosaurs has been revived by numerous discoveries of new and sometimes remarkably preserved specimens, which have enlarged and changed our picture of this group. The volume begins with descriptions of several new pterosaurs from the Triassic, Jurassic and Cretaceous of Europe, North and South America, and Africa. Following this, alternative hypotheses of pterosaur phytogeny and evolution are put forward. Several papers discuss the functional anatomy of pterosaurs and its implications for aerial locomotion. The study of pterosaur footprints provides important new evidence concerning their terrestrial locomotion, and this approach is used in several contributions. A developing aspect of pterosaur research is bone histology, as shown by the final papers in this collection.