Testate amoebae are a diverse group of shelled protists frequently used as model organisms in microbial biogeography. Relatively few species have been reported for the Southern Hemisphere, however, it remains unclear whether this lower diversity is real or an artifact of under-sampling or misidentifications, which would reduce their potential to address macroecological questions. We evaluated testate amoebae diversity from the full range of habitats occurring within two Tierra del Fuego peatlands and compared it with the reported diversity for the area and from the Northern Hemisphere peatlands. We recorded 87 species, of which 69 are new for the region and 45 of them probably new to science and likely to have restricted geographical distributions. Combined with previous studies, the total diversity of testate amoebae only from Tierra del Fuego peatlands now reaches 119, as compared with 183 reported from all Northern Hemisphere peatlands. Our results demonstrate that the number of Gondwanian and Neotropical endemic testate amoeba may be substantially higher than currently known. Previous reports of Holarctic taxa in Tierra del Fuego may result from forcing the identification of morphotypes to the descriptions in the most common literature (force-fitting) South American species into species common in literature from other regions.

遗嘱变形虫是一组多样化的带壳原生生物，经常用作微生物生物地理学中的模式生物。南半球报道的物种相对较少，但是，目前尚不清楚这种较低的多样性是真实存在的还是样本不足或错误识别的产物，这会降低它们解决宏观生态问题的潜力。我们评估了两个火地岛泥炭地内所有栖息地的变形虫多样性，并将其与该地区和北半球泥炭地报告的多样性进行了比较。我们记录了 87 种，其中 69 种是该地区的新物种，其中 45 种可能是科学上的新物种，并且可能在地理分布上受到限制。结合以往的研究，仅来自火地岛泥炭地的有遗嘱变形虫的总多样性现在达到 119 种，而北半球所有泥炭地报告的有 183 种。我们的研究结果表明，冈瓦尼亚和新热带地区特有的遗嘱变形虫的数量可能比目前已知的要多得多。先前关于火地岛全北分类群的报告可能是由于将最常见的文献（强制拟合）南美物种中的形态类型识别为其他地区文献中常见的物种。