Pterosaurs, a Mesozoic group of flying archosaurs, have become a focal point for debates pertaining to the impact of sampling biases on our reading of the fossil record, as well as the utility of sampling proxies in palaeodiversity reconstructions. The completeness of the pterosaur fossil specimens themselves potentially provides additional information that is not captured in existing sampling proxies, and might shed new light on the group's evolutionary history. Here we assess the quality of the pterosaur fossil record via a character completeness metric based on the number of phylogenetic characters that can be scored for all known skeletons of 172 valid species, with averaged completeness values calculated for each geological stage. The fossil record of pterosaurs is observed to be strongly influenced by the occurrence and distribution of Lagerstätten. Peaks in completeness correlate with Lagerstätten deposits, and a recovered correlation between completeness and observed diversity is rendered non-significant when Lagerstätten species are excluded. Intervals previously regarded as potential extinction events are shown to lack Lagerstätten and exhibit low completeness values: as such, the apparent low diversity in these intervals might be at least partly the result of poor fossil record quality. A positive correlation between temporal patterns in completeness of Cretaceous pterosaurs and birds further demonstrates the prominent role that Lagerstätten deposits have on the preservation of smaller bodied organisms, contrasting with a lack of correlation with the completeness of large-bodied sauropodomorphs. However, we unexpectedly find a strong correlation between sauropodomorph and pterosaur completeness within the Triassic-Jurassic, but not the Cretaceous, potentially relating to a shared shift in environmental preference and thus preservation style through time. This study highlights the importance of understanding the relationship between various taphonomic controls when correcting for sampling bias, and provides additional evidence for the prominent role of sampling on observed patterns in pterosaur macroevolution.

中文翻译：

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保存偏见控制着翼龙的化石记录

翼龙是中生代飞行的主龙类群，已成为有关采样偏差对我们阅读化石记录的影响以及采样代理在古多样性重建中的效用的争论的焦点。翼龙化石标本本身的完整性可能会提供现有采样代理中未捕获的额外信息，并可能为该组的进化历史提供新的线索。在这里，我们通过字符完整性度量来评估翼龙化石记录的质量，该度量基于可以对 172 个有效物种的所有已知骨骼进行评分的系统发育特征的数量，并计算每个地质阶段的平均完整性值。翼龙的化石记录被观察到受到 Lagerstätten 的发生和分布的强烈影响。完整性的峰值与 Lagerstätten 矿床相关，当排除 Lagerstätten 物种时，完整性和观察到的多样性之间恢复的相关性变得不显着。以前被视为潜在灭绝事件的区间显示缺乏 Lagerstätten 并且表现出低完整性值：因此，这些区间中明显的低多样性可能至少部分是化石记录质量差的结果。白垩纪翼龙和鸟类完整性的时间模式之间的正相关进一步证明了 Lagerstätten 沉积物在保存较小的身体生物方面的突出作用，与大型蜥脚类恐龙的完整性缺乏相关性形成鲜明对比。然而，我们出乎意料地发现，在三叠纪-侏罗纪，而不是白垩纪，蜥脚类恐龙与翼龙的完整性之间存在很强的相关性，这可能与环境偏好的共同转变有关，从而随着时间的推移保存风格。本研究强调了在校正采样偏差时了解各种埋葬控制之间关系的重要性，并为采样对翼龙宏观进化中观察到的模式的突出作用提供了额外的证据。可能与环境偏好的共同转变有关，从而随着时间的推移保存风格。本研究强调了在校正采样偏差时了解各种埋葬控制之间关系的重要性，并为采样对翼龙宏观进化中观察到的模式的突出作用提供了额外的证据。可能与环境偏好的共同转变有关，从而随着时间的推移保存风格。本研究强调了在校正采样偏差时了解各种埋葬控制之间关系的重要性，并为采样对翼龙宏观进化中观察到的模式的突出作用提供了额外的证据。