Brachiopods dominated the seafloor as a primary member of the Paleozoic fauna. Despite the devastating effects of the end-Permian extinction, the group recovered during the early Mesozoic only to gradually decline from the Jurassic to today. This decline likely had multiple causes, including increased predation and bioturbation-driven substrate disruption, but the role of changing substrate is not well understood. Given the importance of substrate for extant brachiopod habitat, we documented Mesozoic–Cenozoic lithologic preferences and morphological changes to assess how decreasing firm-substrate habitat may have contributed to the brachiopod decline. Compared with bivalves, Mesozoic brachiopods occurred more frequently and were disproportionately abundant in carbonate lithologies. Although patterns in glauconitic or ferruginous sediments are equivocal, brachiopods became more abundant in coarser-grained carbonates and less abundant in fine-grained siliciclastics. During the Jurassic, brachiopod species rarely had abraded beaks but tended to be more convex with a high beak, potentially consistent with a non-analogue lifestyle resting on the seafloor. However, those highly convex morphotypes largely disappeared by the Cenozoic, when more terebratulides had abraded beaks, suggesting closer attachment to hard substrates. Rhynchonellides disproportionately declined to become a minor component of Cenozoic faunas, perhaps because of less pronounced morphological shifts. Trends in lithologic preferences and morphology are consistent with bioturbation-driven substrate disruption, with brachiopods initially using firmer carbonate sediments as refugia before adapting to live primarily attached to hard surfaces. This progressive habitat restriction likely played a role in the final brachiopod decline, as bioturbating ecosystem engineers transformed benthic habitats in the Mesozoic and Cenozoic.

中文翻译：

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生物扰动驱动的底物干扰在中生代腕足动物衰退中的作用

作为古生代动物群的主要成员，腕足类动物在海底占主导地位。尽管二叠纪末期灭绝造成了毁灭性的影响，但该群体在中生代早期恢复了，只是从侏罗纪逐渐衰落到今天。这种下降可能有多种原因，包括捕食增加和生物扰动驱动的底物破坏，但改变底物的作用尚不清楚。鉴于底物对现存腕足动物栖息地的重要性，我们记录了中生代 - 新生代岩性偏好和形态变化，以评估减少坚固的底物栖息地可能如何导致腕足动物衰退。与双壳类动物相比，中生代腕足类动物的出现频率更高，并且在碳酸盐岩性中异常丰富。尽管在海绿石或铁质沉积物中的模式是模棱两可的，但腕足类动物在粗粒碳酸盐岩中变得更加丰富，而在细粒硅质碎屑岩中则较少。在侏罗纪期间，腕足类物种很少有磨损的喙，但往往更凸出高喙，这可能与在海底休息的非模拟生活方式一致。然而，那些高度凸出的形态类型在新生代大部分消失了，当时更多的 terebratulides 已经磨损了喙，表明更紧密地附着在硬质基质上。Rhynchonellides 不成比例地下降成为新生代动物群的次要组成部分，这可能是因为形态变化不太明显。岩性偏好和形态的趋势与生物扰动驱动的基质破坏一致，腕足类动物最初使用较硬的碳酸盐沉积物作为避难所，然后才适应主要附着在坚硬表面上的生活。随着生物扰动生态系统工程师改变了中生代和新生代的底栖栖息地，这种渐进的栖息地限制可能在腕足动物的最终衰退中发挥了作用。