The Cenozoic genus Terebratula seems to be an exception to the post-Permian trend in brachiopod retreat to offshore habitats, because it was species rich and numerically abundant in warm-temperate shallow-water environments in the Mediterranean and the Paratethys realms. This was so despite the general dominance of bivalves and the pervasive bioturbation and predation pressure during the Neogene. Terebratula, however, went extinct in the Calabrian (Pleistocene). The optimal environmental conditions for Terebratula during its prime are poorly known. The Águilas Basin (SE Spain) is an ideal study area to investigate the habitat of Terebratula, because shell beds of this brachiopod occur there cyclically in early Pliocene deposits. We evaluate the paleoecological boundary conditions controlling the distribution of Terebratula by estimating its environmental tolerances using benthic and planktic foraminiferal and nannoplanktic assemblages and oxygen isotopes of the secondary layer brachiopod calcite. Our results suggest that Terebratula in the Águilas Basin favored oligotrophic to mesotrophic, well-oxygenated environments at water depths of 60–90 m. Planktic foraminiferal assemblages and oxygen isotopes point to sea-surface temperatures between ~16°C and 22°C, and bottom-water temperatures between 17°C and 24°C. The analyzed proxies indicate that Terebratula tolerated local variations in water depth, bottom temperature, oxygenation, productivity, and organic enrichment. Terebratula was probably excluded by grazing pressure from well-lit environments and preferentially occupied sediment-starved, current-swept upper offshore habitats where coralline red algae were absent. Narrow temperature ranges of Terebratula species might have been a disadvantage during the high-amplitude seawater temperature fluctuations that started about 1 Ma, when the genus went extinct.

中文翻译：

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限制浅水腕足动物分布的环境因素

新生代属蝾螈似乎是二叠纪后腕足类动物撤退到近海栖息地趋势的一个例外，因为它在地中海和Paratethys领域的暖温带浅水环境中物种丰富且数量丰富。尽管在新近纪期间双壳类动物普遍占主导地位并且普遍存在生物扰动和捕食压力，但情况仍然如此。蝾螈然而，在卡拉布里亚（更新世）灭绝。最佳环境条件蝾螈在其鼎盛时期鲜为人知。Águilas 盆地（西班牙东南部）是研究蝾螈，因为这种腕足类动物的壳床周期性地出现在上新世早期的沉积物中。我们评估控制分布的古生态边界条件蝾螈通过使用底栖和浮游有孔虫和超浮游组合以及次层腕足类方解石的氧同位素来估计其环境耐受性。我们的结果表明蝾螈在 Águilas 盆地，水深 60-90 m 有利于贫营养到中营养、氧合良好的环境。浮游有孔虫组合和氧同位素表明海面温度在 ~16°C 和 22°C 之间，底水温度在 17°C 和 24°C 之间。分析的代理表明蝾螈耐受水深、底部温度、氧化、生产力和有机物富集的局部变化。蝾螈可能被光线充足的环境的放牧压力排除在外，并且优先占据没有珊瑚红藻的沉积物匮乏、海流横扫的上层近海栖息地。狭窄的温度范围蝾螈在大约 1 Ma 开始的高幅度海水温度波动期间，当该属灭绝时，该物种可能是一个劣势。