The paleobiogeography of Early–Middle Devonian (Pragian–Eifelian) brachiopods from West Gondwana was assessed to determine any potential controls (regional climatic differences or global eustasy) that may have driven bioregionalization. The Pragian–Eifelian interval of West Gondwana was examined because work by previous authors suggested that this was a period when regionally extensive areas of provincialism among marine invertebrates were present and most pronounced. Factors of particular interest in this study were the controls over brachiopod bioregionalization at high (60°–90°) southern latitudes, which the Malvinokaffric Realm is thought to have entirely occupied. A large presence-absence data matrix was compiled consisting of the occurrences of 206 genera from 17 localities across West Gondwana, and an array of multivariate methods (cluster analysis, nonmetric multidimensional scaling, and network analysis) was employed to assess regional bioregionalization trends. The results of our study suggest that regional climatic differences brought on by latitudinal effects were the determining driver for bioregionalism of brachiopods during the Pragian–Eifelian, and these trends were coincident with a global cooling period during the Early–Middle Devonian. Our study further suggests that of the three regional paleobiogeographic realms thought to be present in West Gondwana during the Early–Middle Devonian (Eastern Americas, Old World, and Malvinokaffric), only the Malvinokaffric Realm is valid as a single biogeographic area. Its area, however, is reduced; it is interpreted to have been a second-order biogeographic area and not a first-order area as suggested by previous authors. Given these factors, we suggest a new demonym for this area, the “Malvinoxhosan,” given the racially charged connotations of “Malvinokaffric.” We present a new biogeographic framework for West Gondwana that is free of preconceived biogeographic area and rank biases, with the understanding that a more globally expansive study should be undertaken to elucidate these areas and their rank within the correct hierarchy. Two first-order paleobiogeographic areas are recognized in West Gondwana and are named according to their latitudinal extent, namely, the high-latitude (60°S–90°S) and temperate-latitude (30°S–60°S) bioregions. The temperate-latitude bioregion consists of a single second-order paleobiogeographic area, the “Colombian–West African” bioregion. Two second-order bioregions are present in the high-latitude bioregion, namely, the Amazonian and Malvinoxhosan bioregions. Here, the Amazonian (∼50°S–70°S), compositionally, was an intermediate region between the Colombian–West African (∼30°S–50°S) and Malvinoxhosan (70°S–90°S) end members. Latitudinal effects may also have been responsible for dividing the Malvinoxhosan bioregion into two tentative third-order paleobiogeographic areas, namely, the Andeo–South African (∼70°S–80°S) and the Paraná (∼80°S–90°S) bioregions.

中文翻译：

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高纬度泥盆纪腕足动物早期至中度主义和高地生物区划：以冈瓦纳西南部为例

评估了来自西贡多瓦纳的早中中期泥盆纪（古希腊-伊非利亚）腕足动物的古生物地理学，以确定可能驱动生物区域化的任何潜在控制措施（区域气候差异或全球狂喜）。考察了西贡多瓦纳的Pragian-Eifelian间隔，因为以前的作者的工作表明，这是一个时期，在这一时期中，海洋无脊椎动物中存在区域性广泛的省级自治区，这一现象最为明显。在这项研究中特别感兴趣的因素是在南部高纬度（60°–90°）上控制腕足动物生物区域化的过程，据认为Malvinokaffric领域已完全占据了这一位置。汇总了一个庞大的不在场数据矩阵，该矩阵由来自西贡多瓦纳（West Gondwana）的17个地区的206个属组成，并采用了一系列的多变量方法（聚类分析，非度量多维标度和网络分析）来评估区域生物区域化趋势。我们的研究结果表明，纬向效应带来的区域性气候差异是普拉格-伊非利亚时期腕足动物生物区域性的决定性驱动因素，这些趋势与泥盆纪早期-中期的全球降温时期相吻合。我们的研究进一步表明，在早至中泥盆世时期（东美洲，旧世界和马尔维诺科夫里奇）西部冈瓦纳存在的三个区域古生物地理学领域中，只有马尔维诺夫科夫领域是有效的单个生物地理区域。但是，它的面积减少了；它被解释为是二级生物地理区域，而不是以前的作者所建议的一级区域。考虑到这些因素，鉴于种族歧视性的“ Malvinokaffric”，我们建议为该区域起一个新的别名，即“ Malvinoxhosan”。我们提出了一个新的西冈瓦纳生物地理框架，该框架没有预先设想的生物地理区域和等级偏差，但有一项理解，即应进行更广泛的全球研究，以阐明这些地区及其在正确等级中的等级。冈瓦纳西部有两个一级古生物地理区域，并根据其纬度范围命名，即高纬度（60°S–90°S）和温带纬度（30°S–60°S）生物区域。温带-纬度生物区由一个单一的二阶古生物地理区域组成，“哥伦比亚－西非”生物区域。高纬度生物区中有两个二级生物区，即亚马逊河和马尔维诺霍桑生物区。在这里，亚马逊河地区（〜50°S–70°S）在组成上是介于哥伦比亚–西非（〜30°S–50°S）和马尔维诺桑（70°S–90°S）末端之间的中间区域。 。纬度效应也可能导致将Malvinoxhosan生物区分为两个初步的三阶古生物地理区域，即安第奥-南非（〜70°S-80°S）和巴拉那州（〜80°S-90°S）。 ）生物区域。是介于哥伦比亚-西非（〜30°S–50°S）和Malvinoxhosan（70°S–90°S）终端成员之间的中间区域。纬度效应也可能导致将Malvinoxhosan生物区分为两个初步的三阶古生物地理区域，即安第奥-南非（〜70°S-80°S）和巴拉那州（〜80°S-90°S）。 ）生物区域。是介于哥伦比亚-西非（〜30°S–50°S）和Malvinoxhosan（70°S–90°S）终端成员之间的中间区域。纬度效应也可能导致将Malvinoxhosan生物区分为两个初步的三阶古生物地理区域，即安第奥-南非（〜70°S-80°S）和巴拉那州（〜80°S-90°S）。 ）生物区域。