Intensive sampling of the Tulong Formation in South Tibet has facilitated the construction of a highly-resolved middle and late Smithian ammonoid succession. The new biostratigraphical sequence comprises the middle Smithian Brayardites compressus beds, Nammalites pilatoides beds, and the Nyalamites angustecostatus beds followed by the late Smithian Wasatchites distractus beds and Glyptophiceras sinuatum beds. This faunal succession correlates very well with that of other Tethyan sequences such as the Salt Range (Pakistan), Spiti (India), Oman and South China. The Smithian faunal sequence from Tulong contains several taxa with broad geographic distribution (e.g., Owenites, Paranannites spathi, Shigetaceras, Wasatchites), thus enabling correlation with faunal successions from areas outside the Tethys (e.g., USA, British Columbia, Arctic Canada, South Primorye, Siberia). Early Smithian ammonoid faunas are almost absent in Tulong because of a preservation bias (absence of carbonate rocks). Five new ammonoid genera (Brayardites, Nammalites, Nyalamites, Shigetaceras, Tulongites) and six new species (Brayardites crassus, Brayardites compressus, Prionites involutus, ?Subflemingites compressus, Tulongites xiaoqiaoi, Urdyceras tulongensis) are described.

中文翻译：

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藏南土龙的史密（早三叠世）菊石

对藏南吐龙组的密集采样促进了高分辨率中晚期史密斯阶的构建。新的生物地层序列包括中史密斯 Brayardites compressus 层、Namalites pilatoides 层和 Nyalamites angustecostatus 层，其次是晚期 Smithian Wasatchites 分心层和 Glyptophiceras sinuatum 层。这种动物群演替与其他特提斯山脉的演替非常相关，例如盐岭（巴基斯坦）、斯皮提（印度）、阿曼和华南地区。Tulong 的 Smithian 动物群序列包含几个地理分布广泛的分类群（例如，Owenites、Paranannites spathi、Shigetaceras、Wasatchites），因此能够与来自特提斯群岛以外地区（例如，美国、不列颠哥伦比亚省、加拿大北极地区、西伯利亚南滨海边疆区）。由于保存偏差（没有碳酸盐岩），图龙几乎没有早期的史密夫级菊石动物群。描述了五个新的菊花属（Brayardites、Nammalites、Nyalamites、Shigetaceras、Tulongites）和六个新种（Brayardites crassus、Brayardites compressus、Prionites involutus、?Subflemingites compressus、Tulongites xiaoqiaoi、Urdyceras tulongensis）。