Article: Ornithodesmus – a maniraptoran theropod dinosaur from the Lower Cretaceous of the Isle of Wight, England

The holotype and only specimen of Ornithodesmus duniculus, a sacrum from the late Wealden (= Barremian) of the Isle of Wight, is redescribed and is shown not to be pterodactyloid as previously described. Comparison with sacral vertebrae of pterodactyloids and of advanced theropod dinosaurs shows it to resemble most closely those of the small theropod Saurornithoides. Because O. duniculus is the type species of Ornithodesmus, the genus is transferred to the Theropoda. It is assigned to the Troodontidae with uncertainty, because of the limited nature of the holotype. Ornithodesmus duniculus cannot be diagnozed within the Troodontidae and is a nomen vanum within the family. If it is a troodontid, it represents the first record of a troodontid from the Wealden of Europe, and also the earliest record of this family. The undoubted pterodactyloid material from the Barremian of the Isle of Wight, ' Ornithodesmus' latidens, requires a new generic name.