Spiders and ants are infrequent types of prey in the diet of spiders. Both spider- and ant-eating were found in thomisid (crab) spiders but their origin remains unclear. Our goal was to gather data on spider- and ant-eating habits in thomisid spiders, construct a family-level phylogeny, and estimate when these habits evolved. Using prey acceptance experiments, we found 21 spider- and 18 ant-eating genera; based on photographic evidence there were 14 spider- and 20 ant-eating genera; and based on literature there were six spider- and seven ant-eating genera. Altogether we found evidence for 28 spider- and 30 ant-eating genera. We performed the most extensive molecular phylogenetic analysis of Thomisidae to date, using representatives of 75 nominal genera. The resulting topology was congruent with previous studies: Thomisidae were shown to be monophyletic; the genus Borboropactus was identified as a sister group to the remaining thomisids; the current subfamilies emerged as para- or polyphyletic, and Aphantochilinae was monophyletic and rendered Strophiinae paraphyletic within the ‘Thomisus clade’. Ancestral state reconstruction estimated both spider- and ant-eating as ancestral states, suggesting that common ancestors of Thomisidae were euryphagous predators that included spiders but also ants in their diet.

中文翻译：

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蟹蛛（蜘蛛目：Thomisidae）蜘蛛和蚂蚁饮食习惯的进化


蜘蛛和蚂蚁是蜘蛛饮食中不常见的猎物类型。在托米西德（蟹）蜘蛛中发现了吃蜘蛛和吃蚂蚁的行为，但它们的起源仍不清楚。我们的目标是收集托米蜘蛛的蜘蛛和蚂蚁饮食习惯的数据，构建科级系统发育，并估计这些习惯的进化时间。通过接受猎物实验，我们发现了 21 种蜘蛛属和 18 种蚂蚁食性属；根据照片证据，食蜘蛛属有 14 属，食蚁属有 20 属；根据文献，有六种蜘蛛属和七种食蚁属。我们总共发现了 28 种蜘蛛属和 30 种食蚁属的证据。我们使用 75 个名义属的代表对 Thomisidae 进行了迄今为止最广泛的分子系统发育分析。由此产生的拓扑结构与之前的研究一致：Thomisidae 被证明是单系的； Borboropactus 属被确定为其余 thomisids 的姐妹群；目前的亚科是并系或多系的，Aphantochilinae 是单系的，而 Strophiinae 在“Thomisus 进化枝”内是并系的。祖先状态重建估计以蜘蛛和蚂蚁为食的祖先状态，表明Thomisidae的共同祖先是广食性捕食者，其饮食中包括蜘蛛，但也包括蚂蚁。