( M amenchisaurus youngi Pi, Ouyang et Ye, 1996)

Transcription

1 V ERTEBRATA PALASIATICA pp fig. 1,pl. I ( ), ( M amenchisaurus hochuanensis),,, Q (ZDM0126) ( M amenchisau rus hochuanensis Young et Chao, 1972),,, ZDM0126 ( 1), ZDM0126, ( M amenchisaurus youngi Pi, Ouyang et Ye, 1996),,,,,,,,, 46mm, ;,,,, :

2 4 : 267, 1 (ZDM0126) Fig. 1 Burial skeleton of M amenchisaurus hochuanensis (ZDM0126) 30 ( O meisaurus tianf uensis He, Li et Cai, 1988) ;,,,,,, ( S hunosaurus lii Zhang, Li et Zeng, 1988), 1550mm, 150 %,,,

3 mm, 232mm,, 374mm, ; 1020mm, 1/ 2, ; ;, 720mm,, 2, 3 ;,,, 140mm : ( 10 ) 313,, (1954) M amenchisaurus const ruct us, M. hochuanensis M. sinocanadorum (Russell and Zheng,1993) M. youngi M. anyuensis (,1996) M. jingyanensis (, 1998 ) M. f uxiensis ( Zigongosaurus f uxiensis,1976) 6 7 :,,,, :, ; 2000km, :, :, 4 : 4 ; :, : ;, ; 4 ; ;, 6, : 20

4 4 : m, 50,,,, 70 %, 70 % 60 %,,, (1954) 1972,, ( 35 ), 1m 80, (,1988) (1989),,, :,,? ;,,, NEW MATERIAL OF MAM ENCHISAU RUS HOCHUAN ENSIS FROM ZIGONG, SICHUAN YE Yong OU YAN G Hui FU Qian2Ming ( Zigong Di nosaur M useum Zigong ) Key words Zigong, Sichuan, Late J urassic, M amenchisaurus hochuanensis Abstract A nearly complete skeleton of sauropod from the Upper J urassic of Zigong, Sichuan, is described in t his paper. The new specimen ( ZDM0126) is included in M. hochuanensis as its main similar features. But it has skull, teeth, the posterior caudals, pectoral girdle and fore limb which are absent in the holotype of M. hochuanensis, therefore, it complements some important features to this species, as follows : The features of the skull is generally similar to M. youngi. The skull is light and of Cam arasau rus2type. The occipital condyle is hemisp herical shaped. The basioccipital process is well developed. The paraoccipital process is well developed, it s distal end is expanded and fan2shaped. The occipital keel of supreoccipital is well developed and t riagle2 shaped in dorsal view. The basipterygoid process of t he basisp henoid is slender. The middle part of the parictal is very narrow, only 46mm in width. No pineal foramen is present. The

5 frontal is thin and wide. The premaxillary is relatively short and thin, with a well developed nasal process. The maxillary is relatively long and large. The dentary is long and t hin wit h relatively droopy anterior end. Teeth are small and spatulate, the crowns are relatively high and narrow. The medial ridges in the internal surface of the crown are well developed. Denticles are well developed on the anterior edge of teeth crown of the unworn teeth. The posterior caudals are fused with each other, their centra are not expended, the neural arch is remarkably expanded and the size of the neural canal and the height of the neural spines increased. In lateral view, t he posterior caudals are cockscomb2shaped. The scapula is large and long, with a slender shaft. The coracoid is pointed and oval2 shaped. The sternum is small and oval2shaped. The clavicle is short, wit h two processes in the proximal end. The humerus is short, almost 70 % the length of the femur. Both the proximal and distal ends are remarkably expanded, t he deltoid crest is not well developed. The ulna is longer than the radius and 70 % the length of the humerus. The proximal end of t he uala is relatively expanded wit h a prominent radiale2fossa. The radius is st raight and flat. The femur is long and flat, its two ends are remarkably expanded. In the known species of M amenchisaurus, cervical, dorsal, sacral, mid2anterior caudals are well preserved except for the posterior caudals. Therefore, the features of the posterior caudals are not known. The new materials show t hat t he posterior caudals are f used wit h each ot her and are expanded and cockscomb2shaped, which differ distinctly f rom t he hammer2shaped tail of S hunosau rus and O meisau rus. We suggest t hat it s posterior caudals have two main functions : it serves not only as a defensive weapon, but also as an acute sense organ. References Dong Z M ( ),Peng G Z( ), Huang D X( ),1989. The discovery of the bony tail club of sauropoda. Vert PalAsiat ( ),27 (3) : (in Chinese with English summary) He X L ( ),Li K( ), Cai K J ( ), The Middle J urassic dinosaur fauna from Dashanpu, Zigong, Sichuan, Vol. 3, Sauropod dinosaurs(2) Omeisaurus tianf uensis. Chengdu : Sichuan Publishing House of Science and Technology (in Chinese with English summary) He X L ( ), Yang S H ( ), Cai K J ( ) et al., New discovery of Mamenchisaurus ( Sauropod dinosaur). In : Papers of geological science research. Beijing : China Economy Press (in Chinese) Hou L H( ),Zhou S W( ),Cao Y S( ),1976. New discovery of sauropod dinosaur from Sichuan. Vert PalAsiat ( ),14 (3) : (in Chinese) Pi X Z( ),Ouyang H( ), Ye Y( ),1996. A new species of sauropod from Zigong, Sichuan. In : Papers of geological science research. Beijing : China Economy Press (in Chinese) Russell D A, Zheng Z, A large mamenchisaurid from the J unggar Basin, Xinjiang, People s Republic of China. Can J Earth Sci, 30 (10 11) : Young C C( ),1954. On a new sauropod from Yiping, Szechuan, China. Sci Sin, 3 : Young C C( ), Zhao X J ( ),1972. Mamenchisaurus hochuanensis. Inst Vert Paleont Paleoanthrop, Monogr, Ser A( ), (8) :1 30 (in Chinese) Zhang Y H ( ), The Middle J urassic dinosaur fauna from Dashanpu, Zigong, Sichuan, Vol. 3, Sauropod dinosaurs(1) S hunosaurus. Chengdu : Sichuan Publishing House of Science and Technology (in Chinese with English summary) Zhang Y H( ),Li K( ),Zeng Q H( ),1998. A new species of sauropod dinosaur from the Upper J urassic of Sichuan Basin, China. J Chengdu Univ of Technol ( ),25 (1) :61 68 (in Chinese with English summary) ( Explanations of Plate ) 1. ( Posterior part of skull), (Right side view), 1/ 4

6 4 : ( Parietal and frontal), (Dorsal view), 1/ 4 3. (Left premaxillary), ( External view), 1/ 4 4. (Right maxillary), ( External view), 1/ 4 5. (Left dentary), ( External view), 1/ 4 6. ( Posterior caudals), (Left side view), 1/ 3 7. (Clavicle), 1/ 6 8. (Left scapula), ( External view), 1/ 20

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