【摘要】 本文研究了峨眉龙一新种,即天府峨眉龙(Omeisaurus tian-fuensis,sp nov.)。新种产于自贡大山铺中侏罗世沙溪庙组下部。标本保存相当完好,材料丰富,是峨眉龙属的重要补充。新材料的发现,进一步说明了峨眉龙属与马门溪龙属有相当密切的关系,本文主张将该两属同归于马门溪龙科中。更多还原

【Abstract】 A new species of Omeisaurus, namely, O. tianfuensis is described. Its localityis Dashanpu, Zigong, Sichuan, 40 km east of the site of Omeisaurus junghsiensis.Both of the horizons belong to lower Shaximiao Formation of middle Jurassic.Omeisaurus tianfuensis is one of the most important members in the middle JurassicDinosaurian Fauna from Dashanpu, where specimens are abundant and someof them are well preserved. It is estimated that as many as tens of individualsare referred to this species. The main features of Omeisaurus tianfuensis are as follows. The skull moderately high and wedge form from the lateral view, themaximun height is at the posterior end of the skull. Supratemporal fenestralarge and elliptical. Orbit nearly oval and its length larger than height.Antorbital fenestra small. Posttemporal fossa and Premaxillary foraminapresented as well. Maxillary relatively high, with a large ascending process.The articular face of the skull and the lower jaw below the dental seriesline. A mandibular foramen is clearly seen. Teeth spatulate. Dental formula:Pm.4, M.11, D. 13--15. Denticles well developed on the anterior border ofthe teeth but poor on the posterior border. vertebral formula: 17 cervicals, 12 dorsals, 4 sacrals and more than 36 caudals. Cervical much longer thandorsal, with a length ratio of 2.8--2.9. Cervical centra opsithocoelous, withwell developed pleurocoel and ventral keel. Cervical neural spines low andextend forward and backward. The lamellae specially developed in the lasttwo cervicals. The cervical ribs extremely long. Dorsal also opsithocoelous,with well developed pleurocoel. Dorsal neural spines not forked. Sacralsco--ossified each other. The anterior caudal slightly amphicoelous, the firstcaudal rib fan--shaped. The chevrons in the middle caudals forked. The pubicpeduncle of ilium robust and situated at the middle of the ilium, but itsischiadic process not developed. The length ratio of fore limb to hind limb80% or more. The length ratio of ulna to humerus about 70%,and the lengthratio of tibia to ?emur about 2/3. The relationship between Omeisaurus and Mamenchisaurus is dis?ssed. Both ofthem should be referred to the same family, namely, Mamenchisauridae. Thediagnosis of Mamenchisauridae is also revised in this paper.更多还原