Reports of preserved cells and other soft tissues in ancient vertebrates, including dinosaurs, have been met with controversy within the field of vertebrate palaeontology. To explain such reports, Schweitzer et al. (2014) hypothesized that iron-mediated radical crosslinking preserves ancient soft tissues in a manner somewhat analogous to histological tissue fixation. In 2018, Wiemann et al. proposed a second hypothesis that these soft tissues were preserved as advanced glycation/lipoxidation end products (AGEs/ALEs). The chemistry underlying these hypotheses, however, remains poorly described for fossil vertebrates.

This review posits a chemical framework describing the persistence of biological “soft” tissues into deep time. The prior iron-mediated radical crosslinking and AGE/ALE mechanisms are re-described in context of established chemistry from a diversity of scientific fields. Significantly, this framework demonstrates the hypotheses presented by Schweitzer et al. (2014) and Wiemann et al. (2018) are, in many cases, subsequent steps of a single, unified reaction mechanism, and not separate hypotheses. Knowledge of the chemical mechanisms underlying vertebrate soft tissue preservation has direct implications for molecular archaeology and palaeontology, including efforts at molecular sequence recovery within the ancient DNA and palaeoproteomic communities. Such implications that are immediately apparent from examining the chemical framework are discussed.

有关古代脊椎动物（包括恐龙）中保存的细胞和其他软组织的报道在脊椎动物古生物学领域引起了争议。为了解释此类报告，Schweitzer 等人。(2014)假设铁介导的自由基交联以某种类似于组织学组织固定的方式保存了古老的软组织。2018 年，Wiemann 等人。提出了第二个假设，即这些软组织被保存为晚期糖基化/脂肪氧化终产物 (AGEs/ALEs)。然而，这些假设背后的化学成分对于化石脊椎动物的描述仍然很差。

这篇综述提出了一个化学框架来描述生物“软”组织在深层时间中的持久性。先前的铁介导的自由基交联和 AGE/ALE 机制在来自不同科学领域的已建立化学的背景下重新描述。值得注意的是，该框架证明了Schweitzer 等人提出的假设。(2014)和维曼等人。(2018)在许多情况下，是单个统一反应机制的后续步骤，而不是单独的假设。了解脊椎动物软组织保存的化学机制对分子考古学和古生物学有直接影响，包括在古代 DNA 和古蛋白质组群落中恢复分子序列的努力。讨论了通过检查化学框架立即显而易见的此类含义。