云南沾益中泥盆世小肢鱼(Microbrachius)一新种

本文记述胴甲鱼类(Antiarchi)小肢鱼(Microbrachius)的一新种——中华小肢鱼(M.sinensis sp.nov.),发现于云南沾益中泥盆世曲靖组上部,这是小肢鱼化石在中国及亚洲_的初次发现,具有重要的生物地层和生物地理学意义。

A NEW SPECIES or MICROBRACHIUS FROM MIDDLE DEVONIAN OF YUNNAN

A new species of Microbrachius (Antiarchi)—M. sinensis described in this paper was collected from the upper part of Qujing Formation (Middle Devonian, Givetian) from Dongshan, Taoyuan, E. Zhanyi County, Yunnan province in 1977—1978 by Yunnan Regional geological team anl the author. Microbrachius dicki Traquair, a genus of the Antiarchi, lived in the late Middle Devonian (upper part of Old Red Sandstone). Its fossils were first found in 1888, in northern Scotland. For almost 90 years after that, no similar fish fossils were unearthed alsewhere in the world. The present Microbrachius material is the first of its kind to be discovered not only in China, but also in East Asia, The Zhanyi fossil has provided a Scientific basis for comparing continental formations and for studying ancient geography. The present species is very similar to M. dicki in shape of plates and distribution of posterior oblique abdominal pit-line groove (dlg_2). But the new species differs from M. dicki in the bigger size, development of the anterior ventral pit (pt_1) and the conspicuous ornament. All the specimens described are deposited in the Museum of Geology, Beijing.