A redescription of ' Megalosaurus ' hesperis (Dinosauria, Theropoda) from the Inferior Oolite (Bajocian, Middle Jurassic) of Dorset, United Kingdom

摘要: ‘Megalosaurus’ hesperis from the Inferior Oolite (Bajocian, Middle Jurassic) of Dorset, UK is redescribed. Several features ‘M.’ demonstrate that it distinct lectotype dentary Megalosaurus: an enlarged, subcircular third alveolus and subcylindrical, anteriorly inclined anterior teeth; Meckelian foramen located almost directly to posterior foramen; low interdental plates; a prominent lip bounding groove ventrally, fossa. Therefore new genus, Duriavenator, erected form combination D. hesperis. possesses two autapomorphies maxilla: deep on dorsal surface jugal process containing numerous pneumatic foramina; array small foramina in ventral part articular for premaxilla. confirm tetanuran affinities hesperis: maxilla; presence band-like dental enamel wrinkles; maxillary 'fenestra' present but takes imperforate fossa (a spinosauroid synapomorphy); paradental wide anteriorly, defining gap between plates medial wall synapomorphy Spinosauridae + Megalosauridae). Older records tetanurans have been proposed, most these refuted detailed re-examination other early reports warranted establish date origin this clade. An Jurassic preferred.