Wellcomia species (Oxyuridae, Syphaciinae) parasitise several families of rodents from Africa, Asia and America with diverse ecological characteristics. A new species of Wellcomia is described based on specimens obtained from the plains viscacha Lagostomus maximus (Chinchillidae) from Argentina. The description includes morphometric and ecological aspects and an emended diagnosis of the genus Wellcomia. In addition, a molecular characterisation (18S rRNA) and an exploratory analysis of the genetic distances of the species included in this genus are provided. The new species, Wellcomia hugoti n. sp., differs from other species of the genus in the morphology of the cephalic plate, the ventral rugose area in males and the vulva in females. The new species showed a low prevalence (7.7%) and a high mean abundance (73.8). The genetic distances detected do not allow a comprehensive assessment of the monophyly of the genus. This is the seventh record of this genus in rodents from the Americas, the second in rodents from Argentina and the first record for the family Chinchillidae.

Wellcomia物种（Oxyuridae、Syphaciinae）寄生于非洲、亚洲和美洲的多个啮齿动物科，具有不同的生态特征。根据从阿根廷平原 viscacha Lagostomus maximus （龙猫科）获得的标本，描述了Wellcomia的一个新种。该描述包括形态和生态方面以及Wellcomia属的修正诊断。此外，还提供了该属物种的分子特征（18S rRNA）和遗传距离的探索性分析。新物种， Wellcomia Hugoti n. sp.，与该属其他物种的不同之处在于头板、雄性腹侧皱纹区和雌性外阴的形态。新物种的流行率较低（7.7%），平均丰度较高（73.8）。检测到的遗传距离不允许对该属的单系性进行全面评估。这是该属在美洲啮齿动物中的第七个记录，在阿根廷啮齿动物中的第二个记录，也是龙猫科的第一个记录。