Monolophosaurus jiangi Zhao and Currie, 1993

Rauhut, Oliver W. M., 2003, The interrelationships and evolution of basal theropod dinosaurs, Special papers in palaeontology 69, pp. 1-213 : 20

Monolophosaurus jiangi Zhao and Currie, 1993

Age . Middle Jurassic.

Occurrence. Wucaiwan Formation, Xinjiang, China.

Diagnosis. Large midline crest on skull, formed by the premaxillae, nasals, lacrimals and anterior ends of the frontals.

Remarks. Monolophosaurus is the only theropod from the Middle Jurassic of China for which good skull material is known ( Text-fig. 5d ; Zhao and Currie 1993). Although its major apomorphic character is the presence of the unusual medial crest on the skull, the postcranium is sufficiently different from that of the probable contemporaneous taxa Gasosaurus , 4Szechuanosaurus' zigongensis, and Xuanhanosaurus to establish it as a separate genus beyond any reasonable doubt.

Figures

text-fig. 5. Skull reconstructions of representatives of Jurassic OTUs in left lateral view, a, Dilophosaurus wetherilli, Early Jurassic (Sinemurian-Pliensbachian), Kayenta Formation, Arizona, USA; based on UCMP V 4214 and V 6468. B, Syntarsus rhodesiensis, Early Jurassic (Hettangian-Sinemurian), Forest Sandstone, Zimbabwe; composite reconstruction based on many isolated skull elements from the National Museum of Natural History in Harare (see Appendix), c, Magnosaurus oxoniensis, Middle Jurassic (Callovian), Oxford Clay, England; based on OUM J 13558, unpreserved elements shaded. D, Monolophosaurus jiangi, Middle Jurassic, Wucaiwan Formation, China; redrawn from Zhao and Currie (1993b). E, Allosaurus fragilis, Late Jurassic (Kimmeridgian-Tithonian), Morrison Formation, USA; based on MOR 693. f, basal bird Archaeopteryx sp., Late Jurassic (Tithonian), lithographic limestones of Solnhofen, Germany; based on Wellnhofer (1974), Elzanowski and Wellnhofer (1996), and the Berlin, Eichstätt, and Munich specimens. G, Ceratosaurus sp., Late Jurassic (Kimmeridgian-Tithonian), Morrison Formation, USA; based on USNM 4735 and UMNH VP 5278. H, Ornitholestes hermanni, Late Jurassic (Kimmeridgian-Tithonian), Morrison Formation, USA, based on AMNH 619. Abbreviations as in Text-figure 4, and: If, lacrimal fenestra; mf, maxillary fenestra; nf, nasal foramen; pmf, promaxillary fenestra. Scale bars represent 10 mm (b, f, h), 50 mm (c) and 100 mm (a, d, e, g).