贵州兴义晚三叠世贵州龙层新发现的鱼类

NEW DISCOVERED FISHES FROM KEICHOUSAURUS BEARING HORIZON OF LATE TRIASSIC IN XINGYI OF GUIZHOU

描述贵州兴义地区贵州龙层中新发现的鱼类 4新属、4新种和一件新材料 ,它们是小鳞贵州鳕 (新属、新种 )GuizhouniscusmicrolepidusLiugen .etsp .nov .,小短体鱼 (新属、新种 )BrachysomusminorLiugen .etsp .nov .,秀丽兴义鱼 (新属、新种 )XingyiagracilisLiugen .etsp .nov .,臀鳞贵州真颌鱼 (新属、新种 )GuizhouellaanalilepidaLiugen .etsp .nov .,和优美贵州弓鳍鱼GuizhouamiabellulaLiuetal.,2 0 0 2的一件新材料。新的发现和研究表明这是一个颇具特色的晚三叠世早期鱼群。文章还简要讨论各新属新种的系统分类位置和该鱼群在整个鱼类进化中的地位 ,着重论述贵州弓鳍鱼Guizhouamia的进化意义及弓鳍鱼科的系统发育问题。

In the fifties of last century Mr. Su De Zao (former Su Te Tsao) of the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, first described three genera and species of fishes from the Keichousaurus bearing horizon in Xingyi of Guizhou, they are Peltopleurus orientalis Su, 1959, Sinoeugnathus kueichowensis Su, 1959, and Asialepidotus shingyiensis Su, 1959. The then five incomplete fish fossils were collected in 1957 by Mr. Cao Zhe Tian of the Guizhou Museum at Langmu, Dazhai village, Tingxiao of Xingyi. Later on, nobody had made futher investigations and studies for more than two decades. It is an interesting comment in the eighties of last century that the search for fantastic stones let to the discovery of abundant and diversified fish fossils from the Keichousaurus bearing horizon in Xingyi of Guizhou. It is very fortunate that we collected some complete and beautiful specimens of fish fossils from a lot of collectors and dealers in fantastic stone. Moreover, in 2001 and in 2002 we went Xingyi to do field exploring and confirmed that they occur really in the Keichousaurus bearing horizon. One among them, that was used as the holotype of a new genus and species of the family Amiidae, had been described initially in 2002 by the first three authors of this paper, and some supplementary descriptions and necessary discussions will be made in this paper. These new discoveries of great importance have helped us more understanding of the fishes from the Keichousaurus bearing horizon, and moreover, the characters of a distinctive fish fauna of the Late Triassic in Xingyi of Guizhou also have appeared more enough. The new forms and new material of Guizhouamia from the Keichousaurus bearing horizon are deseribed as follows.