Department of Zoology and Animal Cell Biology, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Araba, Spain; Biodiversity Research Group CIEA Lucio Lascaray, Avda. Miguel de Unamuno 3, 01006 Araba, Spain.
Center of Natural History, Zoological Museum, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany.
Mol Phylogenet Evol. 2019 Oct;139:106570. doi: 10.1016/j.ympev.2019.106570. Epub 2019 Jul 23.
The subfamily Leptaxinae is included within the highly diverse land snail family Hygromiidae. In the absence of clear diagnostic morphological differences, the subfamily status is currently based solely on molecular information and includes three disjunctly distributed tribes, Leptaxini, Cryptosaccini and Metafruticicolini. However, the phylogenetic relationships among these tribes are not fully resolved and the clustering of some of the genera to the tribes is not statistically supported. To resolve the relationships within Leptaxinae and their position within Hygromiidae, we reconstructed their phylogeny using a multi-locus approach with two mitochondrial genes and eight nuclear markers. The phylogeny was further calibrated and an analysis of ancestral area estimation was carried out to infer the biogeographic history of the group. We elevated Metafruticicolini to subfamily level (Metafruticicolinae) and we restricted Leptaxinae to Cryptosaccini and Leptaxini. The Lusitanian genus Portugala was moved to Leptaxini, previously containing only the Macaronesian genus Leptaxis. Within Cryptosaccini, a new genus strictly confined to the Sierra de la Cabrera (Spain) is described, Fractanella gen. nov. According to our results, Leptaxinae originated in the Early Miocene in the Iberian Peninsula, from which the Macaronesian Islands were colonized. Due to the old split recovered for the divergence between Macaronesian and Iberian lineages, we hypothesize that this colonization may have occurred via the once emerged seamounts located between the archipelagos and the European and African continents, although this could also have occurred through the oldest now emerged islands of Macaronesia. In the Iberian Peninsula, the climatic shift that began during the Middle Miocene, changing progressively from subtropical climate towards the present-day Mediterranean climate, was identified as an important factor shaping the subfamily's diversification, along with Pleistocene climatic fluctuations.
细齿螺亚科隶属于高度多样化的陆地蜗牛科 Hygromiidae。由于缺乏明显的诊断形态差异，该亚科的地位目前仅基于分子信息，包括三个分布不连续的部落，即细齿螺部落、Cryptosaccini 和 Metafruticicolini。然而，这些部落之间的系统发育关系尚未完全解决，并且一些属聚类到部落的情况在统计上没有得到支持。为了解决 Leptaxinae 内部的关系及其在 Hygromiidae 中的位置，我们使用包含两个线粒体基因和八个核标记的多基因方法重建了它们的系统发育。进一步对系统发育进行了校准，并进行了祖先区估计分析，以推断该组的生物地理历史。我们将 Metafruticicolini 提升为亚科水平（Metafruticicolinae），并将 Leptaxinae 限制为 Cryptosaccini 和 Leptaxini。 Lusitanian 属 Portugala 被移至 Leptaxini，以前仅包含 Macaronesian 属 Leptaxis。在 Cryptosaccini 中，描述了一个新的严格限于 Sierra de la Cabrera（西班牙）的属，即 Fractanella gen. nov. 根据我们的结果，Leptaxinae 起源于早中新世的伊比利亚半岛，Macaronesian 群岛就是从那里殖民而来的。由于在 Macaronesian 和伊比利亚谱系之间的分歧中恢复的古老分裂，我们假设这种殖民可能是通过位于群岛和欧洲和非洲大陆之间的曾经出现的海山进行的，尽管这也可能是通过最古老的现在出现的 Macaronesia 岛屿进行的。在伊比利亚半岛，从中新世中期开始的气候转变，逐渐从亚热带气候转变为现在的地中海气候，被确定为塑造亚科多样化的一个重要因素，同时还有更新世气候波动。
