Abstract Conodont ecology of the Early Triassic Smithian–Spathian transition is still poorly understood. Here we use oxygen isotope ratios of monogeneric conodonts from Omani samples to reveal the differences of oxygen isotopic composition between different taxa. Oxygen isotope analyses from Oman reveal that Neogondolella inhabited a deeper part of the water column relative to neospathodids and Icriospathodus. This indicates that species of Neogondolella lived in an environment ca. 1.7 °C cooler than where neospathodids lived. The investigation of conodonts from these Smithian and Spathian sections has also enabled the first recovery of some rarely reported species (e.g., Icriospathodus zaksi, Paullella omanensis sp. nov. Chen and Gladigondolella laii sp. nov. Chen) from Oman. Paullella omanensis sp. nov. was further recovered from Plavno, Croatia, indicating a large geographic distribution, and its value for biostratigraphic correlations. The discovery of these species in both Oman and Croatia expands their geographical distribution.

中文翻译：

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来自阿曼和克罗地亚的史密森和斯帕提安（早三叠世）牙形石及其水深测量显示

摘要 早三叠世史密斯-斯帕斯阶过渡的牙形石生态学仍知之甚少。在这里，我们使用来自阿曼样本的单属牙形石的氧同位素比率来揭示不同类群之间氧同位素组成的差异。来自阿曼的氧同位素分析表明，与 Neospathodids 和 Icriospathodus 相比，Neogondolella 栖息在水体的更深部分。这表明 Neogondolella 的物种生活在一个环境中。比 Neospathodids 生活的地方低 1.7 °C。对来自这些 Smithian 和 Spathian 部分的牙形石的调查也使得首次从阿曼发现了一些很少报道的物种（例如 Icriospathodus zaksi、Paulllella omanensis sp. nov. Chen 和 Gladigondolella laii sp. nov. Chen）。Paulllella omanensis sp. 十一月 进一步从克罗地亚普拉夫诺发现，表明大的地理分布，及其对生物地层相关性的价值。这些物种在阿曼和克罗地亚的发现扩大了它们的地理分布。