Data from: Cryptic species in the mountaintops: species delimitation and taxonomy of the Bembidion breve species group (Coleoptera: Carabidae) aided by genomic architecture of a century-old type specimen

The breve species group includes closely related Bembidion Latreille ground beetles commonly found at high elevation in the mountains of western North America. For several decades, the group has been considered to consist of two species. Here, we present evidence from morphological, molecular and geographic data that the group contains nine species: Bembidion ampliatum, B. breve, B. geopearlis, B. laxatum, B. lividulum, B. oromaia, B. saturatum, B. testatum and B. vulcanix. We describe three species (B. geopearlis, B. oromaia and B. vulcanix) as new and resurrect four previously synonymized names (B. ampliatum, B. lividulum, B. saturatum and B. testatum). Species diversity is highest throughout the Cascades in Oregon and Washington, and Sierra Nevada of California, where up to seven species can occur in sympatry. We resolved challenging nomenclatural issues through analysis of sequences obtained from century-old type specimens by using a novel application of rDNA copy number analysis – an approach that may prove useful for other historical specimens.

短婪步甲类群（breve species group）包含近缘的婪步甲属（Bembidion Latreille）地表甲虫，该类群广泛分布于北美西部山区的高海拔生境。数十年来，该类群一直被认为仅包含2个物种。本研究基于形态学、分子生物学及地理学数据，证实该类群实际包含9个物种，分别为：*Bembidion ampliatum*、*B. breve*、*B. geopearlis*、*B. laxatum*、*B. lividulum*、*B. oromaia*、*B. saturatum*、*B. testatum* 及 *B. vulcanix*。本研究记述了3个新物种（*B. geopearlis*、*B. oromaia* 及 *B. vulcanix*），并恢复了4个此前被异名的有效学名（*B. ampliatum*、*B. lividulum*、*B. saturatum* 及 *B. testatum*）。该类群的物种多样性在俄勒冈州、华盛顿州的喀斯喀特山脉以及加利福尼亚州的内华达山脉达到峰值，局部区域可多达7个物种同域共存。本研究通过一种新的核糖体DNA（rDNA）拷贝数分析方法，对百年馆藏模式标本的测序序列进行分析，解决了长期存在的分类命名难题，该方法或可推广应用于其他历史馆藏标本的相关研究。