Abstract We present two new records and the description of a new fossil species of daddy long-legs spiders of the genus Modisimus Simon, 1893 from the Miocene Aquitanian amber in the state of Chiapas, Mexico. Of the two studied specimens, one of them is described based on adult male: Modisimus chiapanecus sp. nov. It is not possible to assign the second specimen as new species, because the epigynum it is not clearly visible, therefore we are presenting here the description of the female specimen only. Modisimus chiapanecus sp. nov. is the second fossil species of the family Pholcidae described from Mexico, and the 85th species described of the genus so far. The total number of species of Modisimus from Mexico increases to 20, including the new fossil species described herein. These species represent the oldest known fossils records of the subfamily Modisiminae from the Americas and of the genus so far (23 Mya). Additionally, an updated checklist of the extant Mexican species of the genus is provided.

中文翻译：

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来自美洲的蜘蛛亚科 Modisiminae 最古老的化石：描述来自墨西哥琥珀的 Modisimus Simon 属（Araneae：Pholcidae）的新物种以及现存墨西哥物种的清单

摘要 我们提出了两个新的记录和描述，描述了 1893 年来自墨西哥恰帕斯州的中新世阿基坦琥珀的莫迪西姆斯西蒙属的爸爸长腿蜘蛛的新化石物种。在两个研究的标本中，其中一个是基于成年男性描述的：Modisimus chiapanecus sp。十一月 不可能将第二个标本指定为新物种，因为它的上生殖器不清晰可见，因此我们在此仅提供对雌性标本的描述。Modisimus chiapanecus sp. 十一月 是从墨西哥描述的 Pholcidae 科的第二个化石物种，也是迄今为止描述的第 85 个物种。来自墨西哥的莫迪西姆斯的物种总数增加到 20 种，包括这里描述的新化石物种。这些物种代表了迄今为止美洲和该属 (23 Mya) 亚科 Modisiminae 的最古老的已知化石记录。此外，还提供了该属现有墨西哥物种的更新清单。