Middle and late early silurian brachiopod faunas in southwest china .
西南地区早志留世中、晚期腕足动物群。
The fossils show that the bottom of the food chain was dominated by species typical of later triassic marine faunas such as crustaceans , fishes and bivalves and different from preceding ones .
Ammonites are one of extinct marine faunas at subphylum level , living for a length about 300 million-years ; they have high scientific values in stratigraphy and paleontology .
菊石是一类生存了将近3亿年、业已绝灭的海洋动物;它们的化石在地层学和古生物学具有极大的科学价值。
The author of the 1996 study remarked , " the temporal-spatial distribution of cenozoic faunas and floras on the plateau not only shows the climatic conditions in various periods of time , but it also indirectly indicates changes in elevation of the plateau in various periods . "