Graf Daniel L, Jones Hugh, Geneva Anthony J, Pfeiffer John M, Klunzinger Michael W
Biology Department, University of Wisconsin-Stevens Point, Stevens Point, WI 54481, USA.
Department of Anatomy & Histology, University of Sydney, Sydney, NSW 2006, Australia.
Mol Phylogenet Evol. 2015 Apr;85:1-9. doi: 10.1016/j.ympev.2015.01.012. Epub 2015 Feb 7.
The freshwater mussel family Hyriidae (Mollusca: Bivalvia: Unionida) has a disjunct trans-Pacific distribution in Australasia and South America. Previous phylogenetic analyses have estimated the evolutionary relationships of the family and the major infra-familial taxa (Velesunioninae and Hyriinae: Hyridellini in Australia; Hyriinae: Hyriini, Castaliini, and Rhipidodontini in South America), but taxon and character sampling have been too incomplete to support a predictive classification or allow testing of biogeographical hypotheses. We sampled 30 freshwater mussel individuals representing the aforementioned hyriid taxa, as well as outgroup species representing the five other freshwater mussel families and their marine sister group (order Trigoniida). Our ingroup included representatives of all Australian genera. Phylogenetic relationships were estimated from three gene fragments (nuclear 28S, COI and 16S mtDNA) using maximum parsimony, maximum likelihood, and Bayesian inference, and we applied a Bayesian relaxed clock model calibrated with fossil dates to estimate node ages. Our analyses found good support for monophyly of the Hyriidae and the subfamilies and tribes, as well as the paraphyly of the Australasian taxa (Velesunioninae, (Hyridellini, (Rhipidodontini, (Castaliini, Hyriini)))). The Hyriidae was recovered as sister to a clade comprised of all other Recent freshwater mussel families. Our molecular date estimation supported Cretaceous origins of the major hyriid clades, pre-dating the Tertiary isolation of South America from Antarctica/Australia. We hypothesize that early diversification of the Hyriidae was driven by terrestrial barriers on Gondwana rather than marine barriers following disintegration of the super-continent.
淡水贻贝科（软体动物门：双壳纲：蚌目）在大洋洲和南美洲呈间断的跨太平洋分布。先前的系统发育分析估计了该科以及主要亚科类群（Velesunioninae亚科和Hyriinae亚科：澳大利亚的Hyridellini族；Hyriinae亚科：南美洲的Hyriini族、Castaliini族和Rhipidodontini族）之间的进化关系，但分类单元和特征抽样过于不完整，无法支持预测性分类或检验生物地理学假设。我们对代表上述淡水贻贝科分类单元的30个淡水贻贝个体进行了抽样，以及代表其他五个淡水贻贝科及其海洋姐妹类群（三角蛤目）的外类群物种。我们的内类群包括所有澳大利亚属的代表。利用最大简约法、最大似然法和贝叶斯推断，从三个基因片段（核28S、COI和16S线粒体DNA）估计系统发育关系，并且我们应用了用化石年代校准的贝叶斯松弛时钟模型来估计节点年龄。我们的分析发现，淡水贻贝科及其亚科和族的单系性得到了有力支持，以及澳大拉西亚类群（Velesunioninae亚科，（Hyridellini族，（Rhipidodontini族，（Castaliini族，Hyriini族））））的并系性也得到了支持。淡水贻贝科被发现是一个由所有其他现存淡水贻贝科组成的分支的姐妹类群。我们的分子年代估计支持主要淡水贻贝科分支起源于白垩纪，早于南美洲与南极洲/澳大利亚在第三纪的分离。我们假设淡水贻贝科的早期多样化是由冈瓦纳大陆上的陆地屏障驱动的，而不是超级大陆解体后的海洋屏障。
