Microwear-mesowear congruence and mortality bias in rhinoceros mass death assemblages

Although we do not know the cause of death of most fossils, mortality is often associated with ecological stress due to seasonality and other stochastic events (storms, volcanism) that may have caused shifts in feeding ecology preceding death. In these instances, dental microwear, which reflects feeding ecology in a narrow window of time, may provide a biased view of diet. Mesowear, another dental wear proxy based on the morphology of worn cusps, requires macroscopic amounts of dental wear and reflects diet for a longer interval and may be less prone to bias from near-death ecological stress. We compared congruence between microwear and mesowear of North American fossil rhinocerotid mass death assemblages and hunted collections of modern rhinocerotids to test the hypothesis that fossil assemblages yield more incongruous microwear and mesowear results as a result of near-death ecological disturbances. In extant rhinos, both microwear and mesowear are associated with diet and height of th...尽管多数化石个体的死亡原因尚未明确，但死亡事件通常与季节性波动及风暴、火山活动等随机事件引发的生态胁迫相关，此类事件可能导致个体在死亡前出现摄食生态的改变。在此类场景下，能够反映短时间尺度内摄食生态的牙齿微磨耗（dental microwear），可能会对其食性产生有偏推断。而另一种基于磨损齿尖形态的牙齿宏观磨耗（mesowear）替代指标，则需要一定规模的牙齿磨损量，其反映的是更长时段内的食性，且不易受死亡前短期生态胁迫的影响而产生偏差。本研究针对北美犀科（rhinocerotid）动物的集群死亡化石组合（mass death assemblages）与现生犀科动物的狩猎标本馆藏（hunted collections），对比了二者牙齿微磨耗与宏观磨耗之间的一致性（congruence），以此检验如下假说：受死亡前生态扰动的影响，化石组合的微磨耗与宏观磨耗结果会呈现出更高的不一致性。对于现生犀牛而言，牙齿微磨耗与宏观磨耗均与其食性及身高（height of th...）存在关联。