| 摘要: |
| 江苏宜兴西溪、骆驼墩篮蚬(Corbicula)与环棱螺 (Bellamya)计有10种,其中篮蚬8种,环棱螺2种,属种虽然不多,但是个体数量极多。可分成4个组合类群:一是Corbicula fluminea-Corbicula largillierti组合。这个组合类群地质历程长,适应性强,个体数量多,分布广泛;最早发现于青海柴达木盆地第三系,代表古老类群。二是 Corbicula obrutschewi-Corbicula takasaga组合,这个组合类群壳体较大,轮廓三角形,壳长略大于壳高;C. obrutschewi产于河北张家口岔道村附近的下更新统;C. takasaga发现于台湾新竹的上新统苗栗组;但在中、上更新统时期未发现本组合代表,可是到全新世时,宜兴的西溪、骆驼墩又出现本组合代表,似乎是返 祖现象。三是Corbicula celsusapica-Corbicula yixingensis组合。本类群壳体中等大小,厚而膨凸,轮廓高圆三角形,壳高大于壳长,壳顶宽大而高耸,铰板宽,壳顶腔很深;Corbicula celsusapica发现于浙江湖州上更新统,C. yixingensis到目前仅见于宜兴。本组合为长江下游的宜兴和浙江湖州新生代晚期的特有种。四是Bellamya quadrata-Bellamya viviparoides组合。本组合在上更新统至现在的河流、湖泊均有,其中B. quadrata化石发现于江苏新沂上更新统,B. viviparoides化石发现于江苏句容上更新统下蜀组。 |
| 关键词: 篮蚬(Corbicula) 环棱螺(Bellamya) 类群面貌 组合特征 宜兴 |
| DOI： |
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| Study on mollusc Corbicula and Bellamya from Xixi and Luotuodun,Yixing,Jiangsu Province |
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| Abstract: |
| Abundant mollusc specimens, 8 species of corbiculids and 2 species of bellamyids, are found from Xixi and Luotuodun, Yixing, Jiangsu Province. They can be divided into 4 assemblages. (1) Corbicula fluminea-Corbicula largillierti assemblage. This assemblage, with very long geological history and wide distribution, was first found from the Tertiary of the Qaitam Basin in western China. (2) Corbicula obrutschewi-Corbicula takasaga assemblage. The elements of this assemblage are all large, triangular, and with length a little larger than height. Among them, C. obrutschewi was found from the lower Pleistocene of Chadao Village, Zhangjiakou, Hebei Province. C. takasaga was found from the Pliocene Miaoli Formation of Xinzhu, Taiwan in Southeastern China. Although disappeared in the middle and late Pleistocene, the present assemblage was found again from the Quatermary in Xixi and Luotuodun, suggesting a possible evolution reversion. (3) Corbicula celsusapica-Corbicula yixingensis assemblage. The elements of this assemblage are medium in size, high round triangular in shape, and with height larger than length. Shell is thick and inflaged, and plate is broad. Umbo is broad and prominent, with umbo mantle rather deep. Corbicula celsusapica was found from the upper Pleistocene of Huzhou, Zhejiang Province. On the contrary, C. yixingensis was up to now found only in Yixing. The present assemblage is a unique fauna of Yixing and Huzhou area, the middle and lower reaches of the Yangtze River. (4) Bellamya quadrata-Bellamya viviparoides assemblage. This assemblage appears from the upper Pleistocene to recent river and lake. Among the elements of the present assemblage, B. quadrata was found from the upper Pleistocene Xiashu Formation of Jurong, Jiangsu Province. |
| Key words: mollusk Corbicula Bellamya assemblage environment Yixing |
