INTRODUCTION

In Mexico, Pleistocene fossils are frequently found during building or sewage construction, opening of new roads, agricultural plowing or through research in relationship to the first appearance of people. Among others, remains of horse (Equus) and mammoth (Mammuthus) are the most abundant. The 'Instituto Nacional de Antropología e Historia', or otherwise National Institute of Anthropology and History (INAH by its Spanish initials) is the federal agency in charge of verifying and studying the reported findings. As a result, for the past 40 years, a large amount of material has accumulated from the salvage as well as archaeological and paleontological excavations. This material includes the corresponding documentation, and most data are still unpublished.

The mammoth species in the Americas are not clearly understood as number of species and their diagnostic characters are still matters of controversy. Osborn (1942) considered that there were 15 species, while Maglio (1973) only recognised four. Madden (1981), as yet unpublished but widely cited, and Shoshani & Tassy (1996) did the last revisionary works about these taxonomic problems. Madden (1981) pointed to the validity of six species: Mammuthus hayi, M. imperator, M. exilis, M. columbi, M. jacksoni and M. mammonteus. On the other hand, Shoshani & Tassy (1996) agreed on seven species: M. primigenius, M. columbi, M. exilis, M. hayi, M. imperator, M. jeffersonii and M. meridionalis. The same problems are found in Mexico. For example, Silva-Bárcenas (1987), when listing the mammoth remains on deposit at the 'Instituto de Geología, Universidad Nacional Autónoma de México', recorded the genera Elephas and Mammuthus for the country. Another recent study using measurements and dental data, recorded the presence of Mammuthus columbi and M. imperator, assuming that both species lived at the same time at the Late Pleistocene (Polaco Ramos 1983).

In agreement with Agenbroad (1984), it is important to provide published documentation of the mammoth records in collections in order to gain updated knowledge on the distribution and geological time duration of the different species in a region, and also to clarify the taxonomy. Because of that, this work outlines which mammoth species are found in the country, using INAH’s paleontological collection holdings as a base line.