A New and Open Coiled Valvata (Gastropoda) from the Pliocene Koobi Fora Formation of the Turkana Basin, Northern Kenya
A New and Open Coiled Valvata (Gastropoda) from the Pliocene Koobi Fora Formation of the Turkana Basin, Northern Kenya
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肯尼亚北部图尔卡纳盆地上新世 Koobi Fora 地层中的一个新的开放式螺旋状 Valvata（腹足纲）
DOI：
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发表时间：
2010
影响因子：
1.4
通讯作者：
M. Glaubrecht
中科院分区：
文献类型：
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作者：
Henning Scholz;M. Glaubrecht
摘要：利用新的野外采集资料，对肯尼亚Koobi Fora组上新世Burgi上段Valvata juliae新种进行了研究和描述。该物种的壳形态从直螺旋形到平螺旋形到开螺旋形不等。该物种局限于短地层间隔。Valvata juliae被认为是在一次湖侵事件中入侵图尔卡纳盆地的。该物种的开放式盘绕被解释为对湖泊水位波动和三角洲系统出现引起的高水平环境压力的生态表型反应。这些环境条件使得Valvata juliae在入侵图尔卡纳盆地后不久就灭绝了。
Abstract New field collections allow the study and description of Valvata juliae new species from the Pliocene upper Burgi Member of the Koobi Fora Formation of Kenya. The shell morphology of this species varies from trochospiral to planispiral to open coiled. The species is restricted to a short stratigraphic interval. Valvata juliae is considered as an invader of the Turkana Basin during a lacustrine transgression event. The open coiling of the species is interpreted as an ecophenotypic response to a high level of environmental stress caused by lake level fluctuations and emergence of delta systems. These environmental conditions brought Valvata juliae to extinction soon after it invaded the Turkana Basin.