西南极乔治王岛早第三纪遗迹化石

南极乔治王岛始新统化石山组含多种类型遗迹化石，常与鸟类足迹相伴产出。记述的１新遗迹属及所属的５新遗迹种，从遗迹化石形态两侧对称，纵向延伸，缺乏疣足及其它附肢构造等特征看，推测造迹者为软体蠕虫类，很可能属于寡毛纲的动物。这些化石反映了浅水河湖的沉积环境。

EARLY TERTIARY TRACE FOSSILS FROM KING GEORGE ISLAND, WEST ANTARCTICA

Abundant trace fossils were found in the Eocene Fossil Hill Formation, Fildes Pe ninsula, King George Island, West Antarctica. These trails are commonly associat ed with bird tracks. One new ichnogenus ( Gracilichnus ) and five new ichnospe cies ( G. linearis, G. sinualis, G. circularis, G. tubercularis and G. pust ularis ) are proposed in this paper. The tracemakers were considered as thin bi lateral symmetrical wormlike animal (presumably Oligochaeta) on the basis of thr eadlike slender trails. The sediments preserved trails and bird footprints proba bly represent a fluvio lacustrine depositional environment approaching sea coas t or bay. Paleozoic and Mesozoic trace fossils have been reported in Antarctica, parti cularly in Transantarctic Mountains (Tasch, 1976; Ineson, 1987; Buotois and Lope z Angriman, 1991,1992;Woolf, 1990,1993; Cooper and Shergold, 1991). However the Cenozoic trace fossils are poorly known in this continent (Wiedman and Feldmann, 1988) and has not been described from the continental sediments. The trace fossil material described here was found from the Fossil Hill Formatio n of Fildes Peninsula Group, in Fildes Peninsula, King George Island, South Shet land Islands, West Antarctica (Text fig.1), and collected by the second author during the austral summer of 1987-1988(the fourth Chinese Antarctic Expedition) and 1994-1995 (the eleventh Chinese Antarctic Expedition). The flora and bird fo otprints associated with the trace fossils and petrological characteristics indi cate that fossil bearing strata are of fluvio lacustrine depositional environm ent under a humid and warm climate (Covacevich and Rich, 1982; Li Haomin and She n Yanbin, 1990; Shen Yanbin, 1994; Xue Yaosong et al ., 1996). Abundant speci mens with well preserved structures make the study of tracemaker and paleoecolo gical environment possible.