浙江天台晚白垩世蛋化石生物地层研究  

On the Late Cretaceous Fossil Eggs of Tiantai, Zhejiang

作　　者：方晓思[1] 王耀忠 蒋严根 

机构地区：[1]中国地质博物馆,北京100034 [2]宁波地质矿产勘察院,315010 [3]浙江省天台县桐柏电力工程管理局,317200

出　　处：《地质论评》2000年第1期105-112,T001,共9页Geological Review

摘　　要：晚白垩世天台盆地产有丰富的恐龙蛋化石和恐龙骨骼,目前发现17处化石点,分布于街头镇、平桥镇、白鹤镇、坦头镇、屯桥乡以及县城—国清寺—下朱村一带,面积约为230km^2。特别在城关北侧三角区内,面积仅有15km^2,却是天台县化石点集中区域。这些恐龙蛋化石为原地埋藏,产于上白垩统两头塘组和赤城山组。本文初步描述7种类型恐龙蛋化石:天台长形蛋(新种)Elongatoolithus tiantaiensis sp.nov.、国清寺树枝蛋(新种)Dendroolithus guoqingsiensis sp.nov.、张氏巨型长形蛋(新种)Macroelongatoolithus zhangi sp.nov.、张头槽圆形蛋(新种)Spheroolithus zhangtoucaoensis sp.nov.、石嘴湾副圆形蛋(相似种)Paraspheroolithus cf.shizuiwanensis、树枝树枝蛋(相似种)Dendroolithus cf.dendriticus、椭圆形蛋(未定种)Ovaloolithus sp.。Fossil eggs and dinosaur bones are widely distributed in the Late Cretaceous Tiantai basin. Up to now, 17 fossil localities have been found in Tiantai County , covering a total area of about 230 km2. But in the triangular zone, only about 15 km2, there lie the most abundant fossils of Tiantai. The fossils were discovered apparently in-situ mainly in the Chichengshan and Liangtoutang Formations, and 7 types of fossil eggs are described in this paper.Macroelongatoolithus zhangi sp. nov. (P1.I -1-5)Etymology: Named after Professor Zhang Yun, the late Paleontologist in Beijing University.Holotype; Slice No. Zhe-4-2, p1. 1-2,3Diagnosis; The egg is elongate, with the long diameter of 24 cm, the equatorial diameter of 15 cm. The eggshell is thick, about 2 mm. There are densely arrayed vermicular ornaments in the dark gray egg surface. The prismatic and mammillary layers are distinct. The mammillae are wide-rounded, densely-arranged, with radiated lines in basal spheroliteis. The mammillary layer is about 2/5 of the eggshell thickness. The growth line , regularly distributed in the mammalil-lary layer , is curve in each mammilla, which is replaced by waveliked growth lines in prismatic layer. The pore canals are well-developed in mammillary layer with wedge-shaped interval, and become slim and scattered in prismatic layer.Locality and Horizon: Shuangtang quarry, Tiantai County, Zhejiang; lower part of the Upper Cretaceous Chichengshan Fm.Elongotoolithus tiantaiensis sp. nov. (P1. I -6-8)Etymology; Tiantai, the name of the county where the fossil was discovered.Holotype: Slice No. Zhe-7-4, p1. 1-7,8Diagnosis; The egg is long shuttle-shaped, about 11cm in length, with breadth from 2 to 5 cm. The egg surface is slightly rough, and the thin eggshell is 0. 8 mm thick. The prisms are tightly arranged, and the mammillae are obtuse and the basal spheroliteis big. The mammillary layer is about half of the eggshell thickness. A narrow straight brown stripe zone passes through the mammillary layer area above the basal spherilite. T

关 键 词：蛋化石 晚白垩世 赤城山组 两头塘组 生物地层 

分 类 号：P539[天文地球—古生物学与地层学]