New observations from an outcrop of Upper Ordovician Table Mountain Group strata (Matjiesgoedkloof, Western Cape Province, South Africa) have revealed an unexpected ichnofauna that is hosted within diamictites and sandstones that were deposited by a retreating low-latitude (∼30°S) ice sheet during the Hirnantian glaciation. The locality provides a rare window onto animal-sediment interactions in an early Paleozoic ice-marginal shallow-marine environment and contains a trace fossil community with a surprising ichnodiversity and ichnodisparity of burrows, trackways, and trails (Archaeonassa, Diplichnites, Heimdallia, Metaichna, ?Multina, Planolites, Protovirgularia, Skolithos). Exceptional phenomena preserved in the strata include evidence for direct colonization of glacial diamictites by deep-burrowing Heimdallia infauna, and interactions between trackways and dropstones on substrates. Observations from the newly recognized outcrop dramatically expand our understanding of deep-time glacial habitats, demonstrating that deglaciating ice margins had already been colonized by the latest Ordovician. The freshwater influx that would have been associated with such settings implies that faunal associations that were tolerant of brackish water were also established by that time. The locality has further significance because it records the activity of a nearshore animal community contemporaneous with the fauna of the nearby Soom Shale lägerstatte. Combined, these features reveal a paleoecological transect of the diverse marine life that inhabited cold-climate, low-latitude shallow seas around the time of the end-Ordovician deglaciation.

中文翻译：

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冷脚：奥陶纪末期冰川边缘冰缘地层的走道和洞穴（南非桌山集团）

来自上奥陶纪表山群地层（南非西开普省，Matjiesgoedkloof）露头的新观测结果表明，意料不到的鱼科动物生活在由退缩的低纬度（约30°S）冰沉积的铁矾土和砂岩中Hirnantian冰川时期的床单。该地区为早期古生代冰缘浅海环境中的动物-沉积物相互作用提供了一个难得的窗口，并且包含一个痕迹化石群落，其洞穴，走道和小径的奇异多样性和奇异差异（Archaeonassa，Diplichnites，Heimdallia，Metaichna， Multina，Planolites，Protovirgularia，Skolithos）。地层中保存的特殊现象包括通过深挖海姆达利亚（Heimdallia）infauna来直接定居冰川铁矾的证据，以及轨道和底物上的滴石之间的相互作用。新近发现的露头的观测极大地扩展了我们对深层冰川生境的理解，表明冰川消融的冰缘已经被最新的奥陶纪人定殖了。可能与这种环境有关的淡水涌入表明，到那时也已经建立了耐咸水的动物群落。该地点具有进一步的意义，因为它记录了与附近的Soom Shalelägerstatte的动物区系同时期的近岸动物群落的活动。这些特征相结合，揭示了一种多样的海洋生物的古生态学断面，该生物在奥陶纪末期冰消期结束时居住在冷气候，低纬度的浅海中。新近发现的露头的观测极大地扩展了我们对深层冰川生境的理解，表明冰川消融的冰缘已经被最新的奥陶纪人定殖了。可能与这种环境有关的淡水涌入表明，到那时还建立了耐咸水的动物群落。该地点具有进一步的意义，因为它记录了与附近的Soom Shalelägerstatte的动物区系同时期的近岸动物群落的活动。这些特征相结合，揭示了一种多样的海洋生物的古生态学断面，该生物在奥陶纪末期冰消期结束时居住在冷气候，低纬度的浅海中。新近发现的露头的观测极大地扩展了我们对深层冰川生境的理解，表明冰川消融的冰缘已经被最新的奥陶纪人定殖了。可能与这种环境有关的淡水涌入表明，到那时也已经建立了耐咸水的动物群落。该地点具有进一步的意义，因为它记录了与附近的Soom Shalelägerstatte的动物区系同时期的近岸动物群落的活动。这些特征相结合，揭示了一种多样的海洋生物的古生态学断面，该生物在奥陶纪末期冰消期结束时居住在冷气候，低纬度的浅海中。