X-RAY TOMOGRAPHIC MICROSCOPY AS A MEANS TO SYSTEMATICALLY TRACK EXPERIMENTAL DECAY AND FOSSILIZATION
X-RAY TOMOGRAPHIC MICROSCOPY AS A MEANS TO SYSTEMATICALLY TRACK EXPERIMENTAL DECAY AND FOSSILIZATION
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DOI：
10.2110/palo.2021.004
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发表时间：
2021-06
期刊：
影响因子：
1.6
通讯作者：
T. Selly;J. Schiffbauer
中科院分区：
文献类型：
--
作者：
T. Selly;J. Schiffbauer
摘要：基于实验室的衰变实验已经变得普遍用于补充我们对生物如何进入化石记录的理解。然而，这些实验的设计和评估方式的不同，包括定性衰变评分指数的不同叠加在模型生物的可变性上，使得研究之间的任何比较表面上都是不可靠的。在这里，我们介绍了X射线层析显微镜(µCT)作为一种可靠和可重复的软组织腐烂实验产品分析方法的应用。作为概念验证，我们使用了一个相对简单的实验设计，将经典研究作为比较器，并提出了使用µCT来捕获衰变对象的整个体积的分析方案。然后，分割软件允许进行3D体积分析和高分辨率的内部和外部字符识别。我们以薄荷虾(Lysmata Wurdemanni)为模式生物，描述了从样品准备、对比染色、数据收集到结果数据的处理和分析的工作流程，并将我们的结果与以前的农艺研究进行了比较。与传统的定性评分方法相比，这些方法能够以最少的处理改进衰减和内部体积分析的可视化和量化。使用与以前研究相同的评分标准，这项研究揭示了某些特征的相似衰减结果，同时我们还能够更早地检测到其他特征的丢失或改变--重要的是不需要潜在的扭曲样本处理。我们的结论是，在提取衰变进程的定量数据方面，µCT是一种更有效、更直接、更准确的方法，应该在未来的研究中采用，以简化和标准化比较。
Abstract: Laboratory-based decay experiments have become commonly used to supplement our understanding of how organisms enter the fossil record. Differences in how these experiments are designed and evaluated, however, including dissimilarities in qualitative decay-scoring indices superimposed on variability in model organisms, renders any semblance of comparison between studies unreliable. Here, we introduce the utility of X-ray tomographic microscopy (µCT) as a means for reliable and repeatable analysis of soft-tissue decay experiment products. As proof-of-concept, we used a relatively simple experimental design with classic studies as comparators, and present our analytical protocol using µCT for capturing the entire volume of the decay subject. Segmentation software then allows for 3D volume analysis and high-resolution internal and external character identification. We describe the workflow from sample preparation, contrast-staining, and data collection to processing and analysis of the resulting data, using peppermint shrimp (Lysmata wurdemanni) as model organisms, and compare our results to previous taphonomic studies. These methods allow for improved visualization and quantification of decay and internal volume analysis with minimal handling as compared to traditional qualitative scoring methods. Using the same scoring criteria as previous studies, this study revealed similar decay results for certain features, while we were additionally able to detect other feature loss or alteration earlier—importantly without need for potentially distortive sample handling. We conclude that µCT is a more effective, straightforward, and exact means for extracting quantitative data on the progression of decay and should be adopted in future studies, where available, to streamline and standardize comparisons.