Goodingia is a crinoid-parasitic genus of the gastropod family Eulimidae, consisting of two named members: G. varicosa (Schepman, 1909) (type species) and G. capillastericola (Minichev, 1970). Due to their rarity, these species have been scarcely compared with each other. In this study, we assessed the taxonomic and phylogenetic relationships of Goodingia plus an undescribed eulimid species, whose parasitic ecology and shell profile accord with the genus, with morphological and molecular data. Shell resemblance justified a close relationship between the two species of Goodingia. Newly collected specimens of G. capillastericola from Papua New Guinea and Japan were morphologically indistinguishable but were genetically differentiated from each other (uncorrected p distances of 8.1–8.8% in mitochondrial COI sequences). Phylogenetic analysis recovered another crinoid-parasitic genus Annulobalcis as a paraphyletic group to G. capillastericola, suggesting the evolutionary transition of shell shape from slender to globose and of sexual strategy from separate sexes to simultaneous hermaphroditic. Unexpectedly, the Goodingia-like undescribed species was phylogenetically distant from Goodingia and even Annulobalcis. The present eulimid phylogeny also suggested the polyphyly of endoparasitic and radula-less taxa, respectively, and multiple acquisition of the pseudopallium in the endoparasitic taxa.

Goodingia是腹足家族Eulimidae的海百合寄生属，由两个命名成员组成：G. varicosa（Schepman，1909）（类型物种）和G. capillastericola（Minichev，1970）。由于它们的稀有性，几乎没有对它们进行过比较。在这项研究中，我们通过形态学和分子数据，评估了Goodingia加上未描述的eulimid物种的分类学和系统发育关系，eulimid物种的寄生生态和外壳轮廓与该属一致。壳的相似证明了古丁格两种物种之间的密切关系。刚采集的毛细线菌标本来自巴布亚新几内亚和日本的人在形态上没有区别，但在遗传上彼此不同（线粒体COI序列的未校正p距离为8.1–8.8％）。系统发育分析回收的另一个海百合寄生属Annulobalcis作为系群到G. capillastericola，提示壳形状的细长从从分开的两性到同时具有两性进化过渡到球状和性策略。出乎意料的是，类Goodingia的未描述物种与Goodingia乃至无核类的系统发育距离较远。。目前的eulimid系统发育还分别提示了内寄生物类群和无弓形类群的多重性，并在内寄生物类群中多次获得了假苍白。