Two ammonites have been found in porcelaneous limestones of the White Lias Formation traditionally considered to be of Rhaetian (Late Triassic) age at Lavernock Point, south Wales (ST 181 681). These ammonites, named here Neophyllites lavernockensis. sp. nov, are the earliest recorded from the UK. This horizon is located directly above a major negative δ13C isotope anomaly (CIE1) in the Upper Cotham Member that marks the top of the Triassic System and below another negative δ13C isotope anomaly (CIE3). Both correlate with negative δ13C isotope anomalies in the Triassic–Jurassic global boundary stratotype section and point (GSSP) at Kuhjoch, Austria. This establishes the base of the tilmanni Chronozone, Hettangian Stage and Jurassic System in SW Britain within the White Lias Formation at Lavernock Point.

中文翻译：

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来自南威尔士珀纳斯群和英国西南部侏罗系底部的一种新菊石

在威尔士南部拉弗诺克角 (ST 181 681) 的 White Lias 组传统上被认为是雷蒂亚（晚三叠世）时代的石灰岩中发现了两种菊石。这些菊石，在这里命名Neophyllites lavernockensis。sp。nov，是最早记录在英国的。该视界位于主要负δ的正上方13上 Cotham 段的 C 同位素异常 (CIE1)，标志着三叠系的顶部，低于另一个负 δ13C同位素异常（CIE3）。两者都与负 δ 相关13奥地利 Kuhjoch 三叠纪-侏罗纪全球边界层型剖面和点 (GSSP) 中的 C 同位素异常。这奠定了基础蒂尔曼尼位于 Lavernock Point 的 White Lias 组内的英国西南部时间带、Hettangian 阶段和侏罗纪系统。