Rudists of Tibet and the Tarim Basin, China: Significance to Requieniidae Phylogeny
Rudists of Tibet and the Tarim Basin, China: Significance to Requieniidae Phylogeny
复制标题
DOI：
10.1666/09-137.1
复制
发表时间：
2010-05
期刊：
影响因子：
--
通讯作者：
R. Scott;Xia Wan;J. Sha;Shi-Xuan Wen
中科院分区：
文献类型：
--
作者：
R. Scott;Xia Wan;J. Sha;Shi-Xuan Wen
巴雷米亚到马斯特里赫特的碳酸盐岩单元广泛分布于印度板块北缘和晚白垩世和古近纪连续阶段焊接到欧亚大陆上的特提斯构造片上。珊瑚虫、珊瑚和叠层孔虫组成了厚达10米、横向延伸数公里的生物洞穴。一种独特的地方性需虫，Rutonia，与形态相似但更古老，衍生较少的属进行比较。该组合中相关的标本有不确定的必需瓣、单胸膜瓣和两个属，其中三个放射状种被重新描述并重新评估了分类位置。在塔里木盆地西部的塞诺曼尼亚地层中发现了特提斯鲁德种。利用三维形态Raup图进行卷绕形态计量学分析表明，与基质接触的叶门与腹足类基本壳会聚。更多的衍生强盘绕，更年轻的需求类适应于外壳或半动物习性。地层分析证实Requieniidae多样性危机恰逢白垩纪大洋缺氧事件两端阀门几何每个成员似乎是原始的和派生的字符和单独的家庭Requieniidae分成两个演化支,分别是公认的两个亚科。端部是由盘绕的几何形状来定义的，无论塔尖是靠近接触面还是沿着盘绕轴和肌束结构平移。较老的马鼻甲枝具有较低的旋回率LV，从接合处沿旋回轴略微平移；该组由Matheronia（及其Monnieria亚属）、Hypelasma、Lovetchenia、Rutonia和Kugleria组成。在较年轻的分支中，有一个沿盘绕轴翻译的高的风旋LV，由Requienia， Toucasia, Pseudotoucasia, Apricardia， Bayleoidea和Bayleia组成。遗传学家支持这些关系。
Abstract Rudists are a principal biotic component of Cretaceous carbonates in Tibet and in the Western Tarim Basin. Barremian to Maastrichtian carbonate units are widespread on the northern margin of the Indian Plate and in Tethyan tectonic slices that were welded onto Eurasia in successive stages during the Late Cretaceous and Paleogene. In far northwestern Tibet, Barremian-Cenomanian endemic rudists and cosmopolitan orbitolinid foraminifera occupied isolated carbonate platforms in the eastern Tethys. Rudists, corals, and stromatoporoids composed bioherms up to 10 m thick and several kilometers in lateral extent. A unique endemic requieniid rudist, Rutonia, is compared to morphologically similar but older, less derived genera. Associated specimens in this assemblage are indeterminate requieniid valves, monopleurids, and two genera with three radiolitid species that are re-described and taxonomic positions re-evaluated. In southern Tibet, mainly endemic Campanian-Maastrichtian radiolitid rudists and cosmopolitan larger benthic foraminifera contributed to carbonate shelves on the northern Indian Plate near the Cretaceous equator. In the Western Tarim Basin Cenomanian strata yield Tethyan rudist species. Coiling morphometric analysis using the three-dimensional morphology Raup diagram shows that Requieniidae valves in contact with the substrate are convergent with the basic gastropod shell. More derived strongly coiled, younger requieniids were adapted to encrusting or semi-infaunal habits. Stratigraphic analysis confirms that Requieniidae diversity crises coincided with Cretaceous oceanic anoxic events Two end members of valve geometry each appear to be primitive and derived characters respectively and separate the family Requieniidae into two clades that are here recognized as two new subfamilies. The end members are defined by the coiling geometry, whether the spire is close to the plane of commissure or it is translated along the coiling axis and by myophore structures. The older matheroniform clade has a low spirogyrate LV that is translated slightly from the commissure along the coiling axis; this group is composed of Matheronia (and its subgenus Monnieria), Hypelasma, Lovetchenia, Rutonia, and Kugleria. Genera in the younger clade have a tall trochospiral LV that is translated along the coiling axis and consists of Requienia, Toucasia, Pseudotoucasia, Apricardia, Bayleoidea, and Bayleia. Claditics support these relationships.