Origin of the type series and restriction of the type locality of the Mexican shrew, Megasorex gigas (Mammalia, Soricidae)

The genus Megasorex is monotypic and endemic to Mexico, comprising the Mexican shrew, M. gigas (Mammalia, Soricidae). It was described in 1897 by Clinton H. Merriam, based on three specimens collected by Edward W. Nelson and Edward A. Goldman in the State of Jalisco. We have noted that, due to homonymous place names, the precise locality of the type series has been misinterpreted. Through scrutiny of their field journals and other historical records, here we investigated the origin of the type series for this species. To achieve this, we reconstructed the detailed field itinerary associated with the collection of the type series of M. gigas and restricted the type locality to Las Milpillas, approximately 4 km southwest of San Sebastián del Oeste, Jalisco, with a high degree of certainty. The data obtained in this study are available to support taxonomic studies and spatial analyses for biodiversity conservation.