The documentation of proteinaceous soft tissues in fossils from deep time remains controversial. Often this has been attributed to the laboratory or other modes of modern contamination. Here we provide incontrovertible evidence for the preservation of proteinaceous moieties in Maastrichtian dinosaur eggshell using pyrolysis-GC×GC-TOFMS. The presence of nitrogen-bearing organic molecules along with diketodipyrrole suggests that the proteinaceous moieties can survive diagenesis. The preservation of these proteinaceous moieties has been attributed to deposition in a palustrine flat environment under subaerial conditions and entrapment of organic material by the eggshell calcitic units. The present study demonstrates that the preservation of nitrogen-bearing macromolecules in Mesozoic fossil remains is not impossible provided that the depositional environments and diagenetic processes are propitious. The survival of nitrogen-bearing macromolecules in deep time under subaerial depositional settings will open a new avenue of research on soft tissue preservation.

中文翻译：

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晚白垩世恐龙蛋壳蛋白质部分的发现

远古时期化石中蛋白质软组织的记录仍然存在争议。这通常归因于实验室或其他现代污染模式。在这里，我们为使用热解-GC×GC-TOFMS 保存马斯特里赫特恐龙蛋壳中的蛋白质部分提供了无可争议的证据。含氮有机分子和二酮二吡咯的存在表明蛋白质部分可以在成岩作用中存活下来。这些蛋白质部分的保存归因于在地下条件下在沼泽平坦环境中的沉积以及蛋壳方解石单元对有机材料的捕获。目前的研究表明，只要沉积环境和成岩过程有利，中生代化石遗迹中含氮大分子的保存并非不可能。含氮大分子在地下沉积环境下的深层存活将为软组织保存研究开辟新的途径。