Early Cretaceous ichthyosaurs were globally distributed pelagic marine reptiles, but many remains are fragmentary, creating a Northern Hemisphere diversity bias. A rich Hauterivian locality near the Tyndall Glacier inside Torres del Paine National Park in southern Chile yields important new data regarding ichthyosaurian diversity along the Pacific margin of Gondwana. These new data will contribute to clarifying questions regarding ichthyosaur taxonomy and the palaeobiogeographical relationships between the southern Gondwanan and Northern Hemisphere ichthyosaur groups during the Early Cretaceous. Here, we describe three new ichthyosaur specimens from this locality. Two of them are referred to Myobradypterygius hauthali, expanding the distribution of this species from the Barremian of Argentina to the Hauterivian of the Chilean Patagonia. This material shows that M. hauthali differs from Platypterygius platydactylus in forefin construction and scapular morphology, supporting its classification as a separate genus within Platypterygiinae. The third specimen is a large-bodied indeterminate ophthalmosaurine ichthyosaur. This record represents the southernmost record of Ophthalmosaurinae and the first occurrence of this group from the Cretaceous of the Southern Hemisphere. These discoveries show that ophthalmosaurines and platypterygiines continued to occur sympatrically in southernmost Gondwana during the Early Cretaceous, expanding the pattern documented in Europe to the Pacific region.

中文翻译：

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智利和阿根廷早白垩世的 Myobradypterygius hauthali von Huene， 1927 （Ichthyosauria： Ophthalmosauria） 的有效性


早白垩纪鱼龙是分布在全球的中上层海洋爬行动物，但许多遗骸是零散的，造成了北半球的多样性偏差。智利南部托雷斯德尔潘恩国家公园内廷德尔冰川附近一个丰富的 Hauterivian 地区为冈瓦纳太平洋边缘的鱼龙多样性提供了重要的新数据。这些新数据将有助于阐明有关早白垩纪鱼龙分类学和南冈瓦南和北半球鱼龙类群之间的古生物地理关系的问题。在这里，我们描述了来自该地区的三个新的鱼龙标本。其中两个被称为 Myobradypterygius hauthali，将该物种的分布从阿根廷的 Barremian 扩展到智利巴塔哥尼亚的 Hauterivian。该材料表明，M. hauthali 与 Platypterygius platydactylus 在前鳍结构和肩胛形态上有所不同，支持其在 Platypterygiinae 中被归类为一个单独的属。第三个标本是一只体型大、体型不确定的眼龙鱼龙。这一记录代表了 Ophthalmosaurinae 的最南端记录，也是该类群在南半球白垩纪的首次出现。这些发现表明，在早白垩纪期间，眼龙和扁蜥骨继续在最南端的冈瓦纳同源出现，将欧洲记录的模式扩展到太平洋地区。