Abstract The fossil record of chondrichthyans in Argentina is still poorly known. The aim of the present contribution is to describe teeth representing a chondrichthyan assemblage from Man Aike Formation (late Eocene) exposed in the Lago Argentino area, at Santa Cruz province, Argentina. This report includes Striatolamia macrota, Macrorhizodus praecursor, Carcharias sp., a possible member of the family Pristiophoridae, for the Argentine territory. Previous Eocene reports of Striatolamia macrota from Argentina are based on incorrect determination of specimens. The shark association, especially the abundance of lamniforms, may be indicative of litoral and shallow (less than 30 m depth) temperate to cold waters, as suggested by micropaleontological content.

中文翻译：

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阿根廷巴塔哥尼亚圣克鲁斯省始新世晚期的第一个海洋鱼群

摘要 阿根廷软骨鱼类的化石记录仍知之甚少。本贡献的目的是描述代表出露于阿根廷圣克鲁斯省 Lago Argentino 地区的 Man Aike 组（始新世晚期）的软骨鱼类组合的牙齿。本报告包括 Striatolamia macrota、Macrorhizodus praecursor、Carcharias sp.，它可能是 Pristiophoridae 科的成员，在阿根廷境内。以前关于阿根廷大斑纹藻的始新世报告是基于对标本的错误测定。正如微古生物学内容所暗示的那样，鲨鱼协会，尤其是丰富的层状动物，可能表明温带浅水（小于 30 m 深度）温带至冷水。