山东莱阳盆地早白垩世莱阳群的遗迹化石

A PRELIMINARY STUDY OF NONMARINE TRACE FOSSILS FROM THE LAIYANG GROUP (EARLY CRETACEOUS), LAIYANG BASIN, EASTERN CHINA

山东莱阳早白垩世莱阳群自下而上分为瓦屋夼组、林寺山组、止风庄组、水南组、龙旺庄组和曲格庄组 ,为一套河湖相沉积 ,产有较丰富、分异度较高的非海相遗迹化石和兽脚类恐龙足迹化石。共鉴定出遗迹属 11个 ,未定属 1个 ,其中遗迹种 9个 ,未定种 2个。遗迹化石是 :Cochlichnusanguines,Diplocraterion parallelum ,Helminthoidichnitestenuis,Palaeophycustubularis,Planolitesmontanus,Scolicasp .,Scoyeniagracilis,Skolithoslinearis,Taenidiumcameronensis,Thalassinoidessp .;恐龙足迹化石是 :Paragrallatoryangi。这些化石按习性可分为 4类 ,即 :居住构造、爬行迹、觅食迹和牧食迹 ,其中又以前 3种为主。遗迹化石在剖面上的分布不均匀 ,以上部的水南组、龙旺庄、曲格庄 3个组最丰富。

Relatively abundant and diverse nonmarine trace fossils (including small theropod dinosaur footprints) were discovered from the Early Cretaceous Laiyang Group , Laiyang Basin, eastern China. The Laiyang Group, consisting of a sequence of fluvial-lacustrine strata with a thickness of 1,655 m, can be divided into six formations, which are, in ascending order, the Wawukuang, Linsishan, Zhifengzhuang, Shuinan, Longwanzhuang and Qugezhuang Formations. Eleven ichnogenera, including ten invertebrate ones and a dinosaur ichnogenus, and a type of unknown arthropod crawling trace are described in the present paper. The 10 invertebrate inchnogenera are represented by Cochlichnus anguines, Diplocraterion parallelum, Helminthoidichnites tenuis, Palaeophycus tubularis, Planolites montanus, Scolica sp., Scoyenia gracilis, Skolithos linearis, Taenidium cameronensis, Thalassinoides sp.. The dinosaur track is Paragrallator yangi Li et Zhang. Trace fossils are unevenly distributed across the section. The middle formation-the Shuinan Formation, and the upper two formations-the Longwangzhuang Formation and the Qugezhuang Formation yield more abundant and diverse trace fossils than the other three underlying formations. In terms of ethological classification, the trace fossils from the Laiyang Group fall in four categories, which are Domichnia (including ichnogenera Skolithos and Palaeophycus), Repchnia (including Scolicia, the unknown arthropod trace fossil, dinosaur track Paragrallator), Fodinichnia (ichnogenera Helmithoidichnites, Scoyenia, Taenidium, Plan-olites), and Pascichnion (Cochlichnus).