Data from: Taxonomic quality of species descriptions varies over time and with the number of authors, but unevenly among parasitic taxa

Although concerns are being raised about a potential shortage of taxonomists and systematists, recent analyses suggest instead that the number of researchers involved in taxonomic descriptions is higher than ever and that the average number of new species described annually per taxonomist has declined in recent decades. Here, using nine metrics of taxonomic quality, such as the number of morphological traits measured, the number of separate line drawings included, and whether or not gene sequences are provided, we explore variation in taxonomic quality as a function of the number of authors and other potential determinants across 2366 descriptions of parasitic helminths published in 1337 articles between 1980 and 2014. Taxonomic quality has generally increased over time, but unequally among different groups of helminths. For example, the number of scanning electron micrographs per description has risen significantly over time in cestodes and nematodes, but decreased for digeneans. For most metrics used, the greater the number of authors per species description, the higher its quality, suggesting not more taxonomists but more collaborations between taxonomists and experts from other fields to produce more comprehensive species characterizations. Re-descriptions of species were of higher quality than their original descriptions, and the improved quality correlated with the number of years elapsed between them. However, the extent of this improvement varied among helminth species with different host taxa. Overall, our findings provide a note of caution for anyone using trends in the number of species described per author to extrapolate the total number of extant species. They also reveal cultural differences among taxonomists working on different groups of parasites that can serve to identify areas for potential improvement.

尽管学界正就分类学家（taxonomist）与系统学家（systematist）可能面临的人才短缺问题展开探讨，但近期的分析研究却显示，参与物种分类学描述的研究人员数量较以往任何时期都更为庞大，且近数十年来，每位分类学家年均描述新物种的平均数量有所下降。本研究采用9项分类学质量评价指标，包括被测形态性状数量、所附独立线条图幅数以及是否提供基因序列等，针对1980年至2014年间发表于1337篇文献中的2366份寄生蠕虫（parasitic helminths）分类学描述记录，探究了分类学质量随作者数量及其他潜在影响因素的变化规律。整体而言，分类学质量随时间推移呈上升趋势，但不同类群寄生蠕虫的质量提升幅度并不均衡。例如，绦虫（cestodes）与线虫（nematodes）类群的每份描述所附扫描电子显微镜照片（scanning electron micrograph, SEM）数量随时间显著增加，而复殖吸虫（digeneans）类群则呈下降趋势。就本次研究所采用的多数指标而言，单份物种描述的作者数量越多，其分类学质量越高，这表明提升分类学质量并非依赖于增加分类学家的人数，而是需要推动分类学家与其他领域专家开展更多合作，以形成更为全面的物种特征描述。物种的重新描述质量高于其原始描述，且质量提升幅度与两次描述之间的间隔年限呈正相关。不过，这种提升程度因寄生蠕虫所宿主类群的不同而存在差异。总体而言，本研究结果警示那些试图通过每位作者描述的物种数量趋势来推断现存物种总数的研究者需谨慎行事。同时，本研究还揭示了研究不同寄生虫类群的分类学家之间存在的文化差异，这些差异可作为确定潜在优化方向的参考依据。