Data from: Biogeographic and bathymetric determinants of brachiopod extinction and survival during the Late Ordovician Mass Extinction

The Late Ordovician Mass Extinction (LOME) coincided with dramatic climate changes, but there are numerous ways in which these changes could have driven marine extinctions. We use a palaeobiogeographic database of rhynchonelliform brachiopods to examine the selectivity of Late Ordovician – Early Silurian genus extinctions and evaluate which extinction drivers are best supported by the data. The first (latest Katian) pulse of the LOME preferentially affected genera restricted to deeper waters or to relatively narrow (< 35°) palaeolatitudinal ranges. This pattern is only observed in the latest Katian, suggesting that it reflects drivers unique to this interval. Extinction of exclusively deeper-water genera implies that changes in water mass properties such as dissolved oxygen content played an important role. Extinction of genera with narrow latitudinal ranges suggests that interactions between shifting climate zones and palaeobiogeography may also have been important. We test the latter hypothesis by estimating whether each genus would have been able to track habitats within its thermal tolerance range during the greenhouse-icehouse climate transition. Models including these estimates are favoured over alternative models. We argue that the LOME, long regarded as nonselective, is highly selective along biogeographic and bathymetric axes that are not closely correlated with taxonomic identity.

奥陶纪末大灭绝（Late Ordovician Mass Extinction, LOME）与剧烈的气候变化同步发生，但此类气候变化驱动海洋生物灭绝的潜在路径存在多种可能性。本研究基于有铰纲腕足类（rhynchonelliform brachiopods）的古生物地理数据库，分析晚奥陶世—早志留世（Late Ordovician – Early Silurian）的属级灭绝选择性特征，并评估数据最支持哪些灭绝驱动因素。奥陶纪末大灭绝的第一幕（凯迪阶晚期）优先影响局限于深水环境或古纬度范围较窄（<35°）的属级类群。该选择性模式仅见于凯迪阶晚期，表明其反映了该时段独有的驱动因素。仅分布于深水环境的属类灭绝现象暗示，水体性质变化（如溶解氧含量）发挥了重要作用。古纬度范围狭窄的属类灭绝则提示，气候带迁移与古生物地理格局之间的相互作用同样可能为关键驱动因素。我们通过估算每一属类在温室-冰室气候转型期是否能够追踪其热耐受范围内的栖息地，对后一假说进行检验。包含此类估算结果的模型优于其他备选模型。本研究提出，长期被视为无选择性的奥陶纪末大灭绝，实则在生物地理与水深轴上存在显著选择性，且该选择性与分类学身份并无紧密关联。