摘要
形态学和比较研究表明重庆云阳普安中侏罗统沙溪庙组下段发现的一个脊椎可被归入蜥脚类恐龙峨眉龙属一未定种。该中部颈椎的椎体凹/腔构造非常发育以致其显得更加中空而不是坚实,同时该椎体的长度(不包括其前关节髁)和其后关节面长度和高度平均值的比值很高(5.05)。其他特征还包括:椎体长度约为脊椎全高的两倍,椎体腹面中嵴发育,椎体前关节突嵴板和前关节突间板以及椎体后关节突嵴板和后关节突间板间分别围成深而长的空隙,后关节突椎体横突凹的上半部内有一窝腔,上关节突长而低,向后延伸超出后关节突关节面,神经棘前1/3侧面凹陷,前后向长度约为椎体长度的一半。这一发现揭示了峨眉龙新的形态信息,普安恐龙化石点也代表了该属分布的最东缘。
A cervical vertebra recovered from the Middle Jurassic Lower Member of the Shaximiao Formation in Town of Puan, Yunyang County, Chongqing is assigned to an species undeterminata of the sauropod dinosaur Omeisaurus based on morphological and comparative study. The centrum of this mid-cervical is much hollower than solider with extremely developed fossa/foramen complex and has a high ratio(5.05) of its anteroposterior length excluding the articular ball divided by the mean value of the posterior articular surface mediolateral width and dorsoventral height. Additional features of this cervical include central length about twice the total vertebral height, a prominent midline keel on the central ventral surface, deep and long cavities bounded by centroprezygapophyseal lamina/intraprezygapophyseal lamina and centropostzygapophyseal lamina/intrapostzygapophyseal lamina, respectively, a coel on the dorsal half of the postzygapophyseal centrodiapophyseal fossa, long prone epipophysis extending beyond the postzygapophysis facet, anteroposteriorly length of the neural spine about half the length of the centrum, and concavities on the anterior one third lateral surface of the neural spine. Therefore, this discovery reveals new morphological information on Omeisaurus, and this Omeisaurus-bearing Puan dinosaur quarry represents the easternmost occurrence of this genus.
引文
Carballido J L,Pol D,Otero A et al.,2017.A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs.Proc R Soc B,284,doi:10.1098/rspb.2017.1219
Dong Z M,Zhou S W,Zhang Y H,1983.The dinosaurian remains from Sichuan Basin,China.Paleont Sin,New Ser C,162:1-145
Fang X X,Long Q Q,Lu L W et al.,2000.Lower,Middle,and Upper Jurassic subdivision in the Lufeng region,Yunnan Province.In:Editorial Committee of the Proceedings of the Third National Stratigraphical Congress of China eds.Proceedings of the Third National Stratigraphical Congress of China.Beijing:Geological Publishing House.208-214
Goloboff P A,Farris J S,Nixon K C,2008.TNT,a free program for phylogenetic analysis.Cladistics,24:774-786
He X L,Li K,Cai K J et al.,1984.Omeisaurus tianfuensis-a new species of Omeisaurus from Dashanpu,Zigong,Sichuan.J Chengdu Col Geol,2:15-32
He X L,Li K,Cai K J,1988.The Middle Jurassic Dinosaur Fauna from Dashanpu,Zigong,Sichuan,Vol.IV.Sauropod Dinosaurs(2):Omeisaurus tianfuensis.Chengdu:Sichuan Publishing House of Science and Technology.1-143
Huene F von,1932.Die fossile Reptil-Ordnung Saurischia,ihre Entwicklung und Geschichte Teil I and II.Monogr Geol Palaeont,1:1-361
Jiang S,Li F,Peng G Z et al.,2011.A new species of Omeisaurus from the Middle Jurassic of Zigong,Sichuan.Vert PalAsiat,49:185-194
Li K,1988.Research on Omeisaurus luoquanensis sp.nov.In:He X L,Li K,Cai K J eds.The Middle Jurassic Dinosaur Fauna from Dashanpu,Zigong,Sichuan,Vol.IV.Sauropod Dinosaurs(2):Omeisaurus tianfuensis.Chengdu:Sichuan Publishing House of Science and Technology.94-105
Li K,Yang C Y,Hu F,2011.Dinosaur assemblages from the Middle Jurassic Shaximiao Formation and Chuanjie Formation in the Sichuan-Yunnan Basin,China.Volum Jurassica,9:21-42
Li Y Q,He D F,Li D et al.,2018.Sedimentary provenance constraints on the Jurassic to Cretaceous paleogeography of Sichuan Basin,SW China.Gondwana Res,60:15-33
LüJ C,Li S X,Ji Q et al.,2006.New eusauropod dinosaur from Yuanmou of Yunnan Province,China.Acta Geol Sin Engl,80:1-10
Mannion P D,Upchurch P,Barnes R N et al.,2013.Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis(Macronaria)and the evolutionary history of basal titanosauriforms.Zool J Linn Soc,168:98-206
Marsh O C,1878.Principal characters of American Jurassic dinosaurs.Part I.Am J Sci,16:411-416
Ouyang H,Ye Y,2002.The First Mamenchisaurian Skeleton with Complete Skull:Mamenchisaurus youngi.Chengdu:Sichuan Science and Technology Press.1-111
Peng G Z,Ye Y,Gao Y H et al.,2005.Jurassic Dinosaur Faunas in Zigong.Chengdu:Sichuan Publishing Group People’s Press.1-236
Seeley H G,1887.On the classification of the fossil animals commonly named Dinosauria.Proc R Soc Lond,43:165-171
Sekiya T,2011.Re-examination of Chuanjiesaurus anaensis(Dinosauria:Sauropoda)from the Middle Jurassic Chuanjie Formation,Lufeng County,Yunnan Province,southwest China.Mem Fukui Prefect Dinosaur Mus,10:1-54
Sha J G,Shi X Y,Zhou Z H et al.,2010.The Terrestrial Triassic and Jurassic Systems in the Sichuan Basin,China.Hefei:University of Science&Technology of China Press.1-214
Tang F,Jin X S,Kang X M et al.,2001.Omeisaurus maoianus:a Complete Sauropoda From Jingyan,Sichuan.Beijing:China Ocean Press.1-128
Upchurch P,1995.The evolutionary history of sauropod dinosaurs.Philos Trans R Soc Lond B,349:365-390
Upchurch P,Barrett P M,Dodson P,2004.Sauropoda.In:Weishampel D B,Dodson P,Osmólska H eds.The Dinosauria,2nd ed.Berkeley:University of California Press.259-322
Wang J,Ye Y,Pei R et al.,2018.Age of Jurassic basal sauropods in Sichuan,China:a reappraisal of basal sauropod evolution.Geol Soc Am Bull,doi:org/10.1130/B31910.1
Wilson J A,1999.A nomenclature for vertebral laminae in sauropods and other saurischian dinosaurs.J Vert Paleont,19:639-653
Wilson J A,Michael D,Ikejiri T et al.,2011.A nomenclature for vertebral fossae in sauropods and other saurischian dinosaurs.PLoS ONE,6:e17114
Xing L D,Miyashita T,Zhang J P et al.,2015.A new sauropod dinosaur from the Late Jurassic of China and the diversity,distribution,and relationships of mamenchisaurids.J Vert Paleont,35(1):e889701
Young C C,1939.On a new Sauropoda,with notes on other fragmentary reptiles from Szechuan.Bull Geol Soc China,19:279-316
Young C C,1958.New sauropods from China.Vert PalAsiat,2:1-28