the geographical and ecological context of Tamaulipas, a northeastern state in Mexico, outlining its elevation ranges and diverse habitats. The author elaborates on the various physiographic regions within Tamaulipas, such as the Gulf Coastal Plain, Sierra Madre Oriental, and Central Plateau, each contributing to the rich biodiversity present. Alvarez shares his personal experiences in the field and provides insights into the history of mammalogy in the region, indicating the importance of past explorations and studied specimens that contribute to this report. The introduction sets the stage for a detailed analysis of 146 species of mammals recorded from the state, which will be explored in greater depth throughout the publication. (This is an automatically generated summary.)