Data from: A reconsideration of the classification of the spider infraorder Mygalomorphae based on three nuclear genes and morphology (Arachnida: Araneae)

BACKGROUND: The infraorder Mygalomorphae (i.e., trapdoor spiders, tarantulas, funnel web spiders, etc.) is one of three main lineages of spiders. Comprising 15 families, 325 genera, and over 2,600 species, the group is a diverse assemblage that has retained a number of features considered primitive for spiders. Despite an evolutionary history dating back to the lower Triassic, the group has received comparatively little attention with respect to its phylogeny and higher classification. The few phylogenies published all share the common thread that a stable classification scheme for the group remains unresolved. METHODS AND FINDINGS: We report here a reevaluation of mygalomorph phylogeny using the rRNA genes 18S and 28S, the nuclear protein-coding gene EF-1γ, and a morphological character matrix. Taxon sampling includes members of all 15 families representing 58 genera. The following results are supported in our phylognetic analyses of the data: (1) the Atypoidea (i.e., antrodiaetids, atypids, and mecicobothriids) is a monophyletic group sister to all other mygalomorphs; and (2) the families Mecicobothriidae, Hexathelidae, Cyrtaucheniidae, Nemesiidae, Ctenizidae, and Dipluridae are not monophyletic. The Microstigmatidae is likely to be subsumed into Nemesiidae. Nearly half of all mygalomorph families require reevaluation of generic composition and placement. The polyphyletic family Cyrtaucheniidae is most problematic, representing no fewer than four unrelated lineages. CONCLUSIONS: Based on these analyses we propose the following nomenclatural changes: (1) the establishment of the family Euctenizidae (NEW RANK); (2) establishment of the subfamily Apomastinae within the Euctenizidae; and (3) the transfer of the cyrtaucheniid genus Kiama to Nemesiidae. Additional changes include relimitation of Domiothelina and Theraphosoidea, and the establishment of the Euctenizoidina clade (Idiopidae + Euctenizidae). In addition to these changes, we propose a “road map” for future sampling across the infraorder with the aim of solving many remaining vexing questions that plague mygalomorph systematics.

研究背景：原蛛下目（Mygalomorphae，即陷阱蛛、捕鸟蛛、漏斗网蛛等）是蜘蛛的三大主要演化支系之一。该类群涵盖15个科、325个属以及超过2600个物种，是一类保留了诸多蜘蛛原始特征的多样化类群。尽管其演化历史可追溯至三叠纪早期，但学界对其系统发育与高级分类的研究相对匮乏，已发表的少数系统发育研究均表明，该类群的稳定分类方案至今仍未确定。
材料与方法及研究结果：本研究利用18S核糖体RNA基因（18S rRNA）、28S核糖体RNA基因（28S rRNA）、核蛋白编码基因EF-1γ（EF-1γ）以及形态学特征矩阵，对原蛛下目的系统发育关系进行了重新评估。类群采样覆盖了全部15个科的58个属的代表物种。基于对数据的系统发育分析，本研究得到以下结论：（1）Atypoidea类群（即异纺蛛科Antrodiaetidae、螲蟷科Atypidae和Mecicobothriidae科）为单系群，且是其余所有原蛛下目类群的姊妹群；（2）Mecicobothriidae科、六纺蛛科Hexathelidae、长尾蛛科Cyrtaucheniidae、地蛛科Nemesiidae、Ctenizidae科以及Dipluridae科均非单系群。Microstigmatidae科极有可能被并入地蛛科Nemesiidae。近半数的原蛛下目类群需要对其属级组成与分类位置进行重新评估。其中多系的长尾蛛科Cyrtaucheniidae问题最为突出，至少包含4个互不相关的演化支系。
研究结论：基于上述分析结果，我们提出以下分类学修订方案：（1）建立新科Euctenizidae（Euctenizidae，新等级）；（2）在Euctenizidae科内建立Apomastinae亚科（Apomastinae）；（3）将原隶属于长尾蛛科的Kiama属（Kiama）转入地蛛科Nemesiidae。此外，本研究还对Domiothelina类群和Theraphosoidea总科进行了重新界定，并建立了Euctenizoidina演化支（Idiopidae + Euctenizidae）。除上述修订外，我们还提出了针对原蛛下目类群的未来采样“路线图”，以期解决当前困扰原蛛下目系统分类学的诸多尚存争议的难题。