Much has been written about the meaning of ‘dinosaurs’ in Victorian culture. However, during this period extinct reptiles did not fit neatly into a single ‘scientific’ category. The word ‘dinosaur’, which embraced only three of the many extinct reptiles known in 1842 when it was coined, was not in common vernacular use until the end of the century. In the Victorian period, animals we now call ‘dinosaurs’ were widely perceived as part of a more nebulous group of extinct reptiles, including marine saurians and pterodactyls. They were referred to using various combinations of other, often non-scientific, signifiers, and their significance was consequently open to widely divergent interpretations. As a preliminary move towards understanding the significance of extinct reptiles for the Victorians, this paper will survey how they were constructed semantically both among scientific practitioners and wider constituencies, and will survey the range of associations which eventually helped to crystallize the ‘dinosaur’ as a cultural category at the end of the period.