Pleistocene Soricidae from San Josecito Cave, Nuevo Leon, Mexico

In this detailed study, a collection of Pleistocene shrew bones recovered from San Josecito Cave in northern Mexico is examined for the first time. The author compares the dentary fragments to modern and fossil specimens from across North America, identifying one sample as the cinereous shrew (Sorex cinereus) and establishing it as the southernmost known record of the species during the Ice Age. The analysis also reveals a second, distinct group of shrew fragments that belong to another genus, highlighting subtle differences in jaw shape and tooth arrangement.

Beyond the meticulous anatomical work, the paper discusses what these findings suggest about ancient environments. The presence of a typically boreal, moisture‑loving shrew far south implies that the region once supported much wetter conditions than today. By extending the known range of these tiny mammals, the research offers a glimpse into the climatic landscape of Pleistocene Mexico.