陕西横山晚三叠世鱼类游泳遗迹化石新材料

在多次赴化石产地陕西横山县进行大规模化石发掘后，获得一批完整精美的遗迹标本，为其中鱼类游泳遗迹化石标本建立了新种Undichna prava，并重新修订U.britannica,U.tricosta两种的特征，通过遗迹形态恢复鱼体长度为50—96cm，普遍大于以往描述的国内外据遗迹标本恢复的鱼体长度。

NEW EVIDENCES OF LATE TRIASSIC FISH SWIMMING TRACES IN HENGSHAN COUNTY, SHAANXI PROVINCE, CHINA

The authors have visited the Hengshan County, Shaanxi Province, China for a large-scale excavation of fossils several times since they first reported the discovery of Mesozoic fish swimming traces. In the Hengshan County, the original locality of the fossils, a set of complete and exquisite trace specimens have been collected. In particular, U. prava, a new ichnospecies, is proposed on the collected specimens. The criteria for the determination of U. britannica and U. tricosta are revised in this paper. The trace forms are used to reconstruct the fish-body to be at 50-96 cm in length, longer than those of the trace specimens reconstructed inside and outside China.