Data from: Taking the discovery approach in integrative taxonomy: decrypting a complex of narrow-endemic Alpine harvestmen (Opiliones: Phalangiidae: Megabunus)

Species delimitation is fundamental for biological studies, yet precise delimitation is not an easy task, and every involved approach has an inherent failure rate. Integrative taxonomy, a method that merges multiple lines of evidence, can profoundly contribute to reliable alpha taxonomy and shed light on the processes behind speciation. In this study, we explored and validated species limits in a group of closely related Megabunus harvestmen (Eupnoi, Phalangiidae) endemic to the European Alps. Without a priori species hypotheses, we used multiple sources of inference, including mitochondrial and multilocus nuclear DNA, morphometrics, and chemistry. The results of these discovery approaches revealed morphological crypsis and multiple new species within two of the five hitherto known species. Based on our analyses, we discussed the most plausible evolutionary scenarios, invoked the most reasonable species hypotheses, and validated the new species limits. Building upon the achieved rigour, three new species, M. cryptobergomas Muster & Wachter sp. nov., M. coelodonta Muster & Steiner sp. nov., and M. lentipes Muster & Komposch sp. nov., are formally described. In addition, we provide a dichotomous morphological key to the Megabunus species of the Alps. Our work demonstrates the suitability of integrative, discovery-based approaches in combination with validation approaches to precisely characterise species and enabled us to implement nomenclatural consequences for this genus.

物种界定是生物学研究的核心基础之一，然而精准的物种界定绝非易事，所有相关研究方法均存在固有失败率。整合分类学（Integrative taxonomy）作为一种整合多维度证据的研究范式，可为可靠的阿尔法分类学（alpha taxonomy）提供关键性支撑，并为阐明物种形成背后的演化机制提供全新视角。本研究针对欧洲阿尔卑斯山特有类群——一类隶属于长脚盲蛛亚目（Eupnoi）盲蛛科（Phalangiidae）的大盲蛛属（Megabunus）盲蛛，系统探索并验证了其物种界限。本研究未预先设定物种假说，而是采用了多源推断策略，涵盖线粒体DNA（mitochondrial DNA）、多位点核DNA（multilocus nuclear DNA）、形态测量学（morphometrics）及化学特征分析。上述探索性分析结果显示，该类群存在显著的形态隐存（morphological crypsis）现象，且在目前已记载的5个物种中的2个类群内，发现了多个新物种。基于本研究的分析结果，我们探讨了最具合理性的演化情景，提出了最具说服力的物种假说，并验证了新的物种界定标准。依托本研究达成的严谨分析框架，我们正式描述了3个新种：M. cryptobergomas Muster & Wachter sp. nov.、M. coelodonta Muster & Steiner sp. nov.及M. lentipes Muster & Komposch sp. nov.。此外，我们还提供了阿尔卑斯山大盲蛛属物种的二歧式形态检索表（dichotomous morphological key）。本研究证实，整合式探索性分析与验证性分析相结合的方法，可精准完成物种界定工作，并为该属类群的分类命名规范提供了科学依据。