Data from: Are Miquihuana rhadiniformis Barr, 1982 and Pseudamara arenaria (LeConte, 1847) (Coleoptera, Carabidae) sphodrines? Phylogenetic analysis of data from next-generation sequencing of museum specimens resolves the tribal-group relationships of these enigmatic taxa

Miquihuana rhadiniformis Barr, 1982 and Pseudamara arenaria (LeConte, 1847) are enigmatic North American carabid beetles whose tribal-group placement has been in doubt. Both are currently placed in Sphodrini, although Pseudamara has typically been placed in Zabrini by most authors. As these species are relatively rarely collected, neither Miquihuana Barr, 1982 nor Pseudamara Lindroth, 1968 have been sampled in previous phylogenetic studies and attempts to obtain DNA sequences through standard PCR of available specimens failed. We used Illumina sequencing to recover nuclear gene fragments (18S rDNA, 28S rDNA, wingless, and CAD) from pinned M. rhadiniformis and 70%-ethanol-preserved P. arenaria. Combining these data with data from exemplar taxa from Sphodrini, Zabrini, Pterostichini, Platynini, and other, putatively related tribes, we examine the tribal relationships of Miquihuana and Pseudamara. The phylogenetic reconstructions consistently and with high support place M. rhadiniformis with other sphodrines excluding Atranopsina. There is evidence that Miquihuana is a distinct lineage from Sphodrina, but its placement varies among the single gene analyses. Pseudamara arenaria is not a sphodrine, as it nests within Zabrini, supporting the traditional placement. We transfer Pseudamara back to Zabrini based on these molecular data and we present additional morphological insights corroborating these results.

米基瓦纳硬鞘甲（Miquihuana rhadiniformis Barr, 1982）与沙生假步甲（Pseudamara arenaria (LeConte, 1847)）是两类分类地位存疑的北美步甲科甲虫，其族级分类位置长期存在争议。目前二者均被归入耀步甲族（Sphodrini），但多数分类学者通常将假步甲属（Pseudamara）置于扎步甲族（Zabrini）中。由于这两个类群的标本采集量极少，此前的系统发育研究均未涉及米基瓦纳属（Miquihuana Barr, 1982）与假步甲属（Pseudamara Lindroth, 1968），且利用现有标本通过常规聚合酶链式反应（PCR）获取DNA序列的尝试均告失败。本研究采用Illumina测序技术，从针插干燥标本M. rhadiniformis以及保存在70%乙醇中的P. arenaria标本中成功获取了核基因片段（18S rDNA、28S rDNA、无翅基因（wingless）及CAD基因）。本研究将上述序列数据与耀步甲族（Sphodrini）、扎步甲族（Zabrini）、大步甲族（Pterostichini）、广肩步甲族（Platynini）及其他疑似近缘族的代表类群数据进行整合，以此探究米基瓦纳属与假步甲属的族级系统发育关系。系统发育重建结果始终以较高支持度表明，M. rhadiniformis隶属于耀步甲族类群，但并不属于Atranopsina亚族。有证据显示米基瓦纳属是一个独立于耀步甲亚族（Sphodrina）的演化支，但在单基因分析中其分类位置存在一定波动。沙生假步甲并非耀步甲族类群，而是嵌套于扎步甲族（Zabrini）内部，这一结果支持其传统分类地位。基于上述分子数据，本研究将假步甲属重新归入扎步甲族，并补充了形态学证据以佐证该分类结果。