Ullmann Paul V, Macauley Kyle, Ash Richard D, Shoup Ben, Scannella John B
Department of Geology, Rowan University, Glassboro, NJ 08028, USA.
Department of Geology, University of Maryland, College Park, MD 20742, USA.
Biology (Basel). 2021 Nov 17;10(11):1193. doi: 10.3390/biology10111193.
Many recent reports have demonstrated remarkable preservation of proteins in fossil bones dating back to the Permian. However, preservation mechanisms that foster the long-term stability of biomolecules and the taphonomic circumstances facilitating them remain largely unexplored. To address this, we examined the taphonomic and geochemical history of specimen Museum of the Rockies (MOR) 1125, whose right femur and tibiae were previously shown to retain still-soft tissues and endogenous proteins. By combining taphonomic insights with trace element compositional data, we reconstruct the postmortem history of this famous specimen. Our data show that following prolonged, subaqueous decay in an estuarine channel, MOR 1125 was buried in a coarse sandstone wherein its bones fossilized while interacting with oxic and potentially brackish early-diagenetic groundwaters. Once its bones became stable fossils, they experienced minimal further chemical alteration. Comparisons with other recent studies reveal that oxidizing early-diagenetic microenvironments and diagenetic circumstances which restrict exposure to percolating pore fluids elevate biomolecular preservation potential by promoting molecular condensation reactions and hindering chemical alteration, respectively. Avoiding protracted interactions with late-diagenetic pore fluids is also likely crucial. Similar studies must be conducted on fossil bones preserved under diverse paleoenvironmental and diagenetic contexts to fully elucidate molecular preservation pathways.
许多近期的报告表明，在可追溯到二叠纪的化石骨骼中蛋白质保存得非常完好。然而，促进生物分子长期稳定性的保存机制以及促成这些机制的埋藏学环境在很大程度上仍未得到探索。为了解决这个问题，我们研究了落基山博物馆（MOR）1125号标本的埋藏学和地球化学历史，该标本的右股骨和胫骨先前已被证明仍保留着软组织和内源性蛋白质。通过将埋藏学见解与微量元素组成数据相结合，我们重建了这个著名标本的死后历史。我们的数据表明，在河口河道中经历长时间的水下腐烂后，MOR 1125被埋在粗砂岩中，其骨骼在与有氧且可能微咸的早期成岩地下水相互作用时石化。一旦其骨骼成为稳定的化石，它们经历的进一步化学变化就微乎其微。与其他近期研究的比较表明，氧化的早期成岩微环境和成岩环境分别通过促进分子缩合反应和阻碍化学变化来提高生物分子的保存潜力，同时避免与晚期成岩孔隙流体进行长时间相互作用也可能至关重要。必须对保存在不同古环境和成岩背景下的化石骨骼进行类似研究，以全面阐明分子保存途径。
