Disparity fluctuations in Jurassic ammonoids by means of conch geometry
Disparity fluctuations in Jurassic ammonoids by means of conch geometry
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利用海螺几何学研究侏罗纪菊石的差异波动
DOI：
10.1016/j.palaeo.2010.04.023
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
S. Koenemann
中科院分区：
文献类型：
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作者：
Marc S. Simon;D. Korn;S. Koenemann
我们调查了德国南部侏罗纪菊石的形态空间占领的时间模式。对72个生物地层带内的1200个种进行了螺纹轮廓形状的傅立叶分析。形态空间占据的时间模式的三种一般模式可以通过结合范围的总和、方差的总和和形态谱的质心的位置来区分：（1）形态空间停滞，（2）形态空间扩大，和（3）形态空间缩小。我们应用这一分类方案在侏罗纪菊石的研究，表明侏罗纪菊石在德国南部的演化历史可以分为三个阶段，增加形态范围，结束与切口在早期Aalenian，晚期Escherichian，和结束Tithonian。形态差异部分不同的范围，显示出普遍增加在侏罗纪与切口在Toarcian-Aalenian边界，内的Callovian，和晚期的提东。进行二次抽样以及不同的时间分辨率的差异分析的比较显示出显着不同的影响形态空间模式。不同的分辨率和二次采样数据提供了样本大小和范围之和之间的强相关性。
We investigated the Jurassic ammonoids of southern Germany with respect to their temporal patterns of morphospace occupation. A Fourier analysis of whorl outline shapes was performed based on 1200 species within 72 discriminated biostratigraphic zones. Three general modes of temporal patterns in morphospace occupation can be distinguished by combining the sum of range, the sum of variance, and the position of the centroid of the morphological spectrum: (1) Morphospace stasis, (2) morphospace enlargement, and (3) morphospace reduction. We applied this classification scheme in the study of the Jurassic ammonoids, demonstrating that the evolutionary history of Jurassic ammonoids in southern Germany can be subdivided into three phases with increased morphological range, ending with incisions in the early Aalenian, late Bathonian, and end-Tithonian. Morphological variance differs partly from the range, showing a general increase during the Jurassic with incisions at the Toarcian–Aalenian boundary, within the Callovian, and the late Tithonian. A conducted subsampling as well as the comparison of disparity analyses of different temporal resolutions shows strikingly varying effects in morphospace patterns. Different resolutions and subsampled data provide strong correlations between sample size and the sum of range in particular.