Data from: Nuclear genomic signals of the "microturbellarian" roots of platyhelminth evolutionary innovation

Flatworms number among the most diverse invertebrate phyla, and represent the most biomedically significant branch of the major bilaterian clade Spiralia, but to date, deep evolutionary relationships within this group have been studied using only a single locus (the rRNA operon), leaving the origins of many key clades unclear. Here, using a survey of genomes and transcriptomes representing all free-living flatworm orders, we provide resolution of platyhelminth interrelationships based on hundreds of nuclear protein-coding genes, exploring phylogenetic signal through concatenation as well as recently developed consensus approaches. These analyses robustly support a modern hypothesis of flatworm phylogeny, one which emphasizes the primacy of the often-overlooked 'microturbellarian' groups in understanding the major evolutionary transitions within Platyhelminthes: perhaps most notably, we propose a novel scenario for the interrelationships between free-living and vertebrate-parasitic flatworms, providing new opportunities to shed light on the origins and biological consequences of parasitism in these iconic invertebrates.扁形动物（Flatworms）是物种多样性最为丰富的无脊椎动物类群之一，同时也是主要两侧对称类群螺旋动物（Spiralia）中生物医学意义最为突出的分支。但迄今为止，该类群内部的深层演化关系仅通过单一位点（核糖体RNA操纵子，rRNA operon）开展过研究，致使诸多关键类群的起源问题仍未得到澄清。本研究通过对涵盖所有自由生活扁形动物目的基因组与转录组数据进行系统分析，基于数百个核蛋白编码基因解析了扁形动物门（Platyhelminthes）的类群间演化关系，并通过串联法与近年新兴的共识系统发育分析方法探究系统发育信号。本研究的分析结果稳健支持了扁形动物系统发育的现代假说——该假说强调，在阐释扁形动物门内的主要演化过渡事件时，长期被忽视的“微涡虫类（microturbellarian）”类群占据核心地位。尤为关键的是，我们针对自由生活扁形动物与脊椎动物寄生扁形动物之间的演化关系提出了全新的阐释模型，为揭示这类标志性无脊椎动物的寄生起源及其生物学效应提供了全新的研究契机。