Department of Geology, Rowan University, Glassboro, NJ, USA.
Department of Earth and Environmental Science, Temple University, Philadelphia, PA, USA.
Sci Rep. 2020 Sep 23;10(1):15566. doi: 10.1038/s41598-020-72648-6.
The rare earth element (REE) composition of a fossil bone reflects its chemical alteration during diagenesis. Consequently, fossils presenting low REE concentrations and/or REE profiles indicative of simple diffusion, signifying minimal alteration, have been proposed as ideal candidates for paleomolecular investigation. We directly tested this prediction by conducting multiple biomolecular assays on a well-preserved fibula of the dinosaur Edmontosaurus from the Cretaceous Hell Creek Formation previously found to exhibit low REE concentrations and steeply-declining REE profiles. Gel electrophoresis identified the presence of organic material in this specimen, and subsequent immunofluorescence and enzyme-linked immunosorbant assays identified preservation of epitopes of the structural protein collagen I. Our results thereby support the utility of REE profiles as proxies for soft tissue and biomolecular preservation in fossil bones. Based on considerations of trace element taphonomy, we also draw predictions as to the biomolecular recovery potential of additional REE profile types exhibited by fossil bones.
稀土元素 (REE) 的组成反映了化石骨骼在成岩作用过程中的化学变化。因此，那些呈现低 REE 浓度和/或 REE 分布特征指示简单扩散、表明最小变化的化石，被提议作为古分子研究的理想候选物。我们通过对先前发现 REE 浓度低且 REE 分布特征呈陡峭下降的白垩纪海克里克组恐龙埃德蒙顿龙保存完好的腓骨进行多种生物分子检测，直接验证了这一预测。凝胶电泳鉴定出该标本中存在有机物质，随后的免疫荧光和酶联免疫吸附试验鉴定出结构蛋白胶原 I 的表位得到了保存。因此，我们的结果支持 REE 分布特征可作为化石骨骼中软组织和生物分子保存的替代物。基于微量元素埋藏学的考虑，我们还对化石骨骼中表现出的其他 REE 分布类型的生物分子回收潜力做出了预测。
