UCE phylogenomics of New World Cryptopone (Hymenoptera: Formicidae) elucidates genus boundaries, species boundaries, and the vicariant history of a temperate-tropical disjunction

The genus Cryptopone Emery contains 25 species of litter and soil ants, 5 of which occur in the Americas. Cryptopone gilva occurs in the southeastern U.S.A. and cloud forests of Mesoamerica, exhibiting an uncommon biogeographic disjunction observed most often in plants. We used phylogenomic data from ultraconserved elements (UCEs), as well as mitogenomes and legacy markers, to investigate phylogenetic relationships, species boundaries, and divergence dates among New World Cryptopone. Species delimitation was conducted using a standard approach and then tested using model-based molecular methods (SNAPP, BPP, SODA, and bPTP). We found that Cryptopone as currently constituted is polyphyletic, and that all the South American species belong to Wadeura Weber, a separate genus unrelated to Cryptopone. A single clade of true Cryptopone occurs in the Americas, restricted to North and Central America. This clade is composed of four species that originated ~4.2 million years ago. One species from the mountains of Guatemala is sister to the other three, favoring a vicariance hypothesis of diversification. The taxonomy of the New World Cryptopone and Wadeura are revised. Taxonomic changes are: Wadeura Weber is resurrected, with new combinations W. guianensis Weber, W. holmgreni (Wheeler), and W. pauli (Fernandes & Delabie); C. guatemalensis (Forel) (rev. stat.) is raised to species, and includes C. obsoleta (Menozzi) (syn. nov.). The following new species are described: Cryptopone gilvagrande, C. gilvatumida, and Wadeura holmgrenita. Cryptopone hartwigi is transferred to Fisheropone (n. comb.). Cryptopone mirabilis (Mackay & Mackay 2010) is a junior synonym of Centromyrmex brachycola (Roger) (syn. nov.).

隐猛蚁属（Cryptopone Emery）包含25种腐殖质与土壤栖息蚁类，其中5种分布于美洲。红褐隐猛蚁（Cryptopone gilva）见于美国东南部及中美洲云雾林，呈现出一种罕见的生物地理间断分布格局，该类格局在植物类群中较为典型。本研究利用超保守元件（ultraconserved elements, UCEs）、线粒体基因组（mitogenomes）以及经典分子标记的系统基因组数据，对新世界隐猛蚁的系统发育关系、物种边界及分化时间展开探究。物种界定先采用标准方法进行，随后通过基于模型的分子方法（SNAPP、BPP、SODA及bPTP）开展验证。研究发现，当前界定的隐猛蚁属为多系群，且所有南美物种均隶属于韦德猛蚁属（Wadeura Weber），该属与隐猛蚁属无亲缘关系。美洲境内仅存在一个真正的隐猛蚁属演化支，其分布局限于北美与中美洲。该演化支包含4个物种，起源时间约为420万年前。来自危地马拉山地的1个物种为其余3个物种的姊妹群，这一结果支持了其多样化过程的地理隔离分化假说。本研究对新世界隐猛蚁属与韦德猛蚁属的分类系统进行了修订，分类学调整如下：恢复韦德猛蚁属（Wadeura Weber）的有效属级地位，新组合包括W. guianensis Weber、W. holmgreni (Wheeler)及W. pauli (Fernandes & Delabie)；重新提升危地马拉隐猛蚁（Cryptopone guatemalensis (Forel)）的种级地位（rev. stat.），并将C. obsoleta (Menozzi)定为其新异名（"syn. nov."）。此外，本文记述了3个新种：大褐隐猛蚁（Cryptopone gilvagrande）、细褐隐猛蚁（Cryptopone gilvatumida）以及霍氏韦德猛蚁（Wadeura holmgrenita，新种）。哈特维希隐猛蚁（Cryptopone hartwigi）被转移至费希尔猛蚁属（Fisheropone），为新组合（"n. comb."）。奇妙隐猛蚁（Cryptopone mirabilis (Mackay & Mackay 2010)）为短足尖尾猛蚁（Centromyrmex brachycola (Roger)）的次异名（"syn. nov."）。