Can fractal dimensions objectivize gastropod shell morphometrics? A case study from Lake Lugu (SW China)

作者：Robert J. Wiese, Kyle Harrington, Kai Hartmann, Manja Hethke, Thomas von Rintelen, Hucai Zhang, Le‐Jia Zhang, Frank Riedel · 发表于：Ecology and Evolution · 年份：2022 · DOI：10.1002/ece3.8622 · 被引用次数：11 · 研究领域：Morphological variations and asymmetry、Evolution and Paleontology Studies、Pleistocene-Era Hominins and Archaeology

Morphometrics are fundamental for the analysis of size and shape in fossils, particularly because soft parts or DNA are rarely preserved and hard parts such as shells are commonly the only source of information. Geometric morphometrics, that is, landmark analysis, is well established for the description of shape but it exhibits a couple of shortcomings resulting from subjective choices during landmarking (number and position of landmarks) and from difficulties in resolving shape at the level of micro-sculpture.With the aid of high-resolution 3D scanning technology and analyses of fractal dimensions, we test whether such shortcomings of linear and landmark morphometrics can be overcome. As a model group, we selected a clade of modern viviparid gastropods from Lake Lugu, with shells that show a high degree of sculptural variation. Linear and landmark analyses were applied to the same shells in order to establish the fractal dimensions. The genetic diversity of the gastropod clade was assessed.The genetic results suggest that the gastropod clade represents a single species. The results of all morphometric methods applied are in line with the genetic results, which is that no specific morphotype could be delimited. Apart from this overall agreement, landmark and fractal dimension analyses do not correspond to each other but represent data sets with different information. Generally, the fractal dimension values quantify the roughness of the shell surface, the resolution of the 3D ...