Site-selectivity analysis of drilling predation traces may provide useful behavioral information concerning a predator interacting with its prey. However, traditional approaches exclude some spatial information (i.e., oversimplified trace position) and are dependent on the scale of analysis (e.g., arbitrary grid system used to divide the prey skeleton into sectors). Here we introduce the spatial point pattern analysis of traces (SPPAT), an approach for visualizing and quantifying the distribution of traces on shelled invertebrate prey, which includes improved collection of spatial information inherent to drillhole location (morphometric-based estimation), improved visualization of spatial trends (kernel density and hotspot mapping), and distance-based statistics for hypothesis testing (K-, L-, and pair correlation functions). We illustrate the SPPAT approach through case studies of fossil samples, modern beach-collected samples, and laboratory feeding trials of naticid gastropod predation on bivalve prey. Overall results show that kernel density and hotspot maps enable visualization of subtle variations in regions of the shell with higher density of predation traces, which can be combined with the maximum clustering distance metric to generate hypotheses on predatory behavior and anti-predatory responses of prey across time and geographic space. Distance-based statistics also capture the major features in the distribution of traces across the prey skeleton, including aggregated and segregated clusters, likely associated with different combinations of two modes of drilling predation, edge and wall drilling. The SPPAT approach is transferable to other paleoecologic and taphonomic data such as encrustation and bioerosion, allowing for standardized investigation of a wide range of biotic interactions.

中文翻译：

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痕迹的空间点模式分析（SPPAT）：一种可视化和量化钻井捕食者的地点选择性模式的方法

钻探捕食痕迹的站点选择性分析可以提供有关捕食者与其猎物相互作用的有用行为信息。然而，传统方法排除了一些空间信息（即过度简化的轨迹位置）并且依赖于分析的规模（例如，用于将猎物骨骼划分为扇区的任意网格系统）。在这里，我们介绍了轨迹的空间点模式分析 (SPPAT)，这是一种可视化和量化有壳无脊椎动物猎物上的轨迹分布的方法，其中包括改进钻孔位置固有的空间信息收集（基于形态测量的估计），改进的可视化空间趋势（核密度和热点映射），以及用于假设检验的基于距离的统计数据（K-,L-，以及对相关函数）。我们通过化石样本的案例研究、现代海滩收集的样本以及对双壳类动物的腹足类动物捕食的实验室喂养试验来说明 SPPAT 方法。总体结果表明，核密度和热点图能够可视化具有较高捕食痕迹密度的壳区域的细微变化，这可以与最大聚类距离度量相结合，以生成关于捕食行为和猎物反捕食反应的假设时间和地理空间。基于距离的统计数据还捕获了猎物骨骼上痕迹分布的主要特征，包括聚集和分离的簇，可能与两种钻孔捕食模式的不同组合有关，边缘钻孔和壁钻孔。