Pacific island land snails exhibit exceptionally high species diversity, morphological diversity, and endemism. Species within superfamily Punctoidea, which contains the Charopidae and Pacific-endemic family Endodontidae, are among the most morphologically spectacular Pacific endemic land snails. The evolution of Pacific island punctoids remains poorly known, due in part to rampant human-induced extinction within this group of minute ground-dwellers. The Belau archipelago (Republic of Palau) with its relatively intact lowland rainforest and limestone karst Rock Islands, is home to many endemic punctoids and presents a unique opportunity to better understand the diversification of one of the most diverse but also imperiled land snail lineages on Pacific islands. For the first time, the diversification of the endemic Pacific punctoid fauna of Belau was studied using Bayesian Inference (BI) and Maximum Likelihood (ML) methods applied to sequences from mitochondrial (COI) and nuclear (ITS2) gene regions. Evolutionary relationships, molecular divergence, disjunct or complex geographic ranges, and ecological similarity among Belau punctoid species, likely reflect species’ long evolutionary history and diversification through geographic isolation. We find no evidence for adaptation in species-level shifts in spire height within Aaadonta endodontids. We also find preliminary evidence for the evolution of premating reproductive isolation in Semperdon species in sympatry, through the study of apertural teeth. In addition, we report the first new endodontid species from living individuals as well the first new genus record from the Belau archipelago in nearly half a century.

中文翻译：

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Belau（帕劳共和国，大洋洲）的点状陆蜗牛的分子系统发育和早产隔离

太平洋岛屿陆生蜗牛表现出异常高的物种多样性、形态多样性和特有性。Punctoidea 总科中的物种包括 Charopidae 和太平洋特有科 Endodontidae，是形态学上最壮观的太平洋特有陆螺之一。太平洋岛屿点状点的进化仍然知之甚少，部分原因是在这群微小的地面居民中，人为引起的灭绝猖獗。贝劳群岛（帕劳共和国）拥有相对完整的低地雨林和石灰岩岩溶岩群岛，是许多地方性点状群落的家园，提供了一个独特的机会来更好地了解太平洋上最多样化但也濒临灭绝的陆地蜗牛谱系之一的多样化岛屿。第一次，使用贝叶斯推理 (BI) 和最大似然 (ML) 方法对来自线粒体 (COI) 和核 (ITS2) 基因区域的序列进行研究，研究了 Belau 地方性太平洋点状动物群的多样化。Belau punctoid 物种之间的进化关系、分子差异、分离或复杂的地理范围以及生态相似性，可能反映了物种通过地理隔离的漫长进化历史和多样化。我们发现没有证据表明在物种水平的尖顶高度变化中存在适应性 可能通过地理隔离反映了物种漫长的进化历史和多样化。我们发现没有证据表明在物种水平的尖顶高度变化中存在适应性 可能通过地理隔离反映了物种漫长的进化历史和多样化。我们发现没有证据表明在物种水平的尖顶高度变化中存在适应性Aaadonta牙髓。通过对孔牙的研究，我们还发现了Semperdon物种中早产生殖隔离进化的初步证据。此外，我们报告了近半个世纪以来来自活体个体的第一个新牙髓物种以及来自 Belau 群岛的第一个新属记录。