Data from: The gastropod family Aporrhaidae in the Lower Cretaceous of the Neuquén Basin, west-central Argentina

The gastropod fauna of the Lower Cretaceous of the Argentinian Neuquén Basin contains three aporrhaid species. Protohemichenopus neuquensis Camacho, 1953 is the most abundant, longest-lived and most geographically widespread of the aporrhaids of this basin, and its protoconch and early teleoconch whorls were unknown until now. The new species Dimorphosoma weaveri features convex to subtly angular spire whorls with opisthocyrt collabral ribs that are more prominent towards the mid-whorl, a bicarinate last whorl with small rounded nodes on the adapical carina, a simple, falcate labral wing which is more or less rectangular proximally and tapering and curving towards its distal end, and a short, straight rostrum. Tylostoma jaworskii Weaver, 1931 is now placed in Harpagodes, and other previous, scattered, coeval records of this genus in the basin are now recognized as part of this single species. It is believed that whereas H. jaworskii preferred shallower-water carbonate settings of low to moderate energy, P. neuquensis and D. weaveri favoured siliciclastic to mixed clastic-carbonate environments, in deeper waters. In spite of its endemic elements, this aporrhaid association depicts a predominantly Tethyan influence.阿根廷内乌肯盆地下白垩统的腹足类动物群（gastropod fauna）包含3个翼口螺科（Aporrhaidae）物种。Protohemichenopus neuquensis Camacho, 1953是该盆地翼口螺科中数量最多、生存时限最长且地理分布最广的类群，其胚壳（protoconch）与早期成壳螺层直至本研究前仍未被报道。新种Dimorphosoma weaveri具有凸至微呈棱角状的螺塔层，其上的后曲斜肋（opisthocyrt collabral ribs）在螺层中部更为突出；末螺层具双脊，近顶脊（adapical carina）上分布有小型圆形结节；外唇翼（labral wing）简单呈镰状，近端大致呈矩形，向远端逐渐收窄并弯曲；壳喙（rostrum）短而直。原Tylostoma jaworskii Weaver, 1931现被归入Harpagodes属，此前该盆地中该属的其他零散同期记录，如今均被证实属于该单一物种。研究表明，H. jaworskii偏好低至中等水动力条件的浅海碳酸盐岩沉积环境，而P. neuquensis与D. weaveri则更青睐深水环境中的硅质碎屑岩或混合碎屑岩-碳酸盐岩沉积体系。尽管该翼口螺类组合存在特有类群，但其整体仍主要表现出特提斯域（Tethyan）的生物地理影响。