Description and palaeobiology of a new species of <i>Libycosaurus</i> (Cetartiodactyla, Anthracotheriidae) from the Late Miocene of Toros-Menalla, northern Chad

The analysis of a large sample of anthracothere remains discovered by the Mission Paléoanthropologique Franco-Tchadienne at Toros-Menalla (TM), Northern Chad, has revealed the occurrence of a single species with a large intraspecific morphological variability. Taxonomic problems triggered the necessity of naming a new species for the TM anthracotheres, <i>Libycosaurus bahri</i> sp. nov. The description of the craniodental remains and the analysis of their variability indicate a marked sexual dimorphism, most probably induced by sex differential growth, helping to reassess the specific diversity of <i>Libycosaurus</i> and its main evolutionary trends in a phylogenetic perspective. The ecological niche occupied by the new species was also further characterized in its semiaquatic, behavioural, and dietary dimensions. On these grounds we suggest that Late Miocene environmental changes, particularly habitat opening and hydrographic network fragmentation related to increased aridity, played a major role in canalizing semi-aquatic specializations and the extinction of the last African anthracotheres, as well as other bothriodontines.http://zoobank.org/urn:lsid:zoobank.org:pub:8C0AD4BD-952D-4A60-94B8-6F7A23332171

对乍得北部托罗斯-梅纳拉（Toros-Menalla, TM）遗址出土、由法-乍得古人类学考察团（Mission Paléoanthropologique Franco-Tchadienne）发现的大量炭兽类（anthracothere）化石标本开展分析后，结果显示该遗址存在一个具有显著种内形态变异的单一物种。受分类学难题所限，我们为该遗址的炭兽类命名新种——*Libycosaurus bahri* sp. nov.。对其颅齿部（craniodental）化石遗骸的描述与变异特征分析表明，该物种存在显著的性别二态性（sexual dimorphism），这大概率由性别差异化生长所导致，该发现有助于从系统发育（phylogenetic）视角重新评估利比亚兽属（*Libycosaurus*）的物种多样性及其主要演化趋势。本新种所占据的生态位（ecological niche）还从半水生习性、行为模式与食性特征多个维度得到了进一步的明确刻画。基于上述研究证据，我们提出：晚中新世（Late Miocene）的环境变化，尤其是与干旱化加剧相关的栖息地开阔化与水文网络破碎化，在塑造半水生特化特征以及最后一批非洲炭兽类及其他双锥齿兽亚科（bothriodontines）物种的灭绝过程中发挥了关键作用。http://zoobank.org/urn:lsid:zoobank.org:pub:8C0AD4BD-952D-4A60-94B8-6F7A23332171

搜集汇总

背景与挑战

背景概述

该数据集聚焦于晚中新世乍得北部Toros-Menalla地区发现的Libycosaurus新物种（Libycosaurus bahri sp. nov.）的描述和古生物学分析。研究基于大量炭兽类遗骸样本，揭示了物种的显著种内形态变异和性二态性，并探讨了其半水生生态位及晚中新世环境变化（如栖息地开放和水文网络破碎化）对非洲炭兽类灭绝的影响。数据集包含相关PDF文件，发布于2014年，涉及生物科学、生态学和进化生物学等领域。