Data from: Three new species in the harvestmen genus Acuclavella (Opiliones, Dyspnoi, Ischyropsalidoidea), including description of male Acuclavella quattuor Shear 1986.

In Shear’s 1986 cladistic analysis of the Ischyropsalidoidea, he described the new genus Acuclavella including four new species from the Pacific Northwest states of Washington and Idaho. Several of these species descriptions were based on very limited sample sizes. Our recent field work has increased by more than an order of magnitude both the number of specimens and known localities for Acuclavella. We use this new material to interpret species limits in Acuclavella using morphometric analyses and DNA sequence data from four gene regions. We sequence for the first time the protein-coding homolog of the WNT2 gene for phylogenetic reconstruction in Opiliones. Our multi-locus phylogeny corroborates a sister relationship between Acuclavella and Ceratolasma, as hypothesized using morphology by Shear (1986). Within Acuclavella, morphometric clusters and reciprocal allelic monophyly allows recognition of three additional species: Acuclavella leonardi sp. n., A. sheari sp. n., and A. makah sp. n. This work also describes the previously unknown male of Acuclavella quattuor, from specimens collected at the type locality. Our research identifies a number of novel morphologies for Acuclavella, including females with four pairs of spines, individuals with three pairs of spines on scute areas I-III, and a population with two pairs of spines disjunct from A. quattuor, which was diagnosed with this spination character. We were unable to assign these populations to existing species, and conservatively do not yet recognize them as new. Intrageneric morphometrics and phylogenetic inference in Acuclavella were often concordant. However, we demonstrate that species delimitation signal would not be detected if only a single line of evidence were utilized.

在希尔（Shear）1986年针对异螯盲蛛总科（Ischyropsalidoidea）的分支系统学分析中，他描述了锐爪盲蛛属（Acuclavella）这一新属，包含采自美国太平洋西北地区华盛顿州与爱达荷州的4个新种。其中数个物种的描述仅基于极为有限的样本量。我们近期的野外工作使得锐爪盲蛛属的标本数量与已知分布点数量均提升了一个数量级以上。我们利用这批新标本，通过形态测量分析以及4个基因区域的DNA序列数据，对锐爪盲蛛属的物种界限进行厘定。我们首次对盲蛛目（Opiliones）中WNT2基因的蛋白编码同源序列进行测序，用于系统发育重建。我们的多位点系统发育树证实了锐爪盲蛛属与角盲蛛属（Ceratolasma）的姊妹群关系，这一假说曾由希尔1986年基于形态学提出。在锐爪盲蛛属内，形态测量聚类结果与等位基因单系性互为印证，据此可确立3个新种：Acuclavella leonardi sp. n.、A. sheari sp. n.以及A. makah sp. n.。本研究还描述了此前未被记录的Acuclavella quattuor雄性标本，其采集自该物种的模式产地。本研究发现了锐爪盲蛛属的多个全新形态特征：包括具有4对棘刺的雌性个体、在背甲区域I-III带有3对棘刺的个体，以及与以该棘刺特征为鉴别依据的A. quattuor地理隔离的仅具2对棘刺的种群。我们无法将这些种群归入已有的物种，因此审慎起见，暂不将其认定为新物种。锐爪盲蛛属内的形态测量分析与系统发育推断结果通常具有一致性。但本研究表明，若仅采用单一证据维度，将无法检测到物种界定的信号。