The Carboniferous–Permian (C–P) Cutler Group in southeastern Utah archives large-scale environmental changes along multiple facies belts, including major sea-level changes and continental aridification that intensified into earliest Permian times. Nevertheless, the stratigraphical position of the C–P boundary within the Cutler Group has been poorly constrained, until now. Here, we report the first biostratigraphically significant conodonts from shallow-water facies of the lower Cutler beds in the vicinity of Valley of the Gods, San Juan County, Utah. Bulk samples were collected from marine carbonate marker beds spanning up to 160 m of section through the middle Rico to Halgaito formations. Productive carbonates yielding diagnostic conodont elements included the informal marker beds: the McKim limestone and the ‘A’ limestone, representing a variety of shallow-water facies. C–P conodonts included Ellisonia conflexa, Hindeodus sp. and Adetognathus spp. We show that the first appearance of Adetognathus sp. B (Henderson), a species known from the C-P interval (latest Gzhelian – early Asselian) of the Canadian Arctic and east-central British Columbia, places the local base of the Permian at or above the ‘A’ limestone in southern San Juan County. The new records reinforce previous age assignments for the Rico–Halgaito transition beds established on the basis of land vertebrate faunachrons (LVFs) and offer a rare datum for correlating marine and terrestrial C–P faunal assemblages in western Pangaea.

中文翻译：

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美国犹他州熊耳国家纪念碑及附近地区的石炭纪-二叠纪牙形石和下卡特勒群的年龄

犹他州东南部的石炭纪-二叠纪 (C-P) 卡特勒群记录了沿多个相带的大规模环境变化，包括主要的海平面变化和大陆干旱化，这些变化在最早的二叠纪时代加剧。然而，直到现在，卡特勒群内 C-P 边界的地层位置一直没有受到很好的约束。在这里，我们报告了犹他州圣胡安县众神谷附近的下卡特勒河床浅水相的第一个具有生物地层学意义的牙形石。大块样品是从跨越中间 Rico 到 Halgaito 地层的长达 160 m 的海相碳酸盐标记床中收集的。产生诊断牙形石元素的生产性碳酸盐包括非正式标记床：McKim 石灰岩和“A”石灰岩，代表各种浅水相。包括 C–P 牙形石Ellisonia conflexa , Hindeodus sp. 和Adetognathus spp。我们表明Adetognathus sp的首次出现。B（亨德森），一种在加拿大北极和不列颠哥伦比亚省中东部的 CP 间隔（最新的 Gzhelian – 早期 Asselian）已知的物种，将二叠纪的当地基部置于圣胡安县南部的“A”石灰岩或上方. 新记录加强了以前基于陆生脊椎动物群落 (LVF) 建立的 Rico-Halgaito 过渡床的年龄分配，并为关联 Pangaea 西部的海洋和陆地 C-P 动物群组合提供了罕见的数据。