Research on Fossil amphibians and reptiles in Mexico, from 1869 to early 2004 (including marine forms but excluding pterosaurs, dinosaurs, and obviously, birds)

The amphibian and reptile fossil record in Mexico is scarce. There have been reported 255 unique taxon/locality/age records from 85 localities. Most fossils are fragmentary and their taxonomic status is difficult to assess; however, some are beautifully preserved, permitting even good cladistic and biogeographical analysis. Among amphibians there are records of caudates and anuras, restricted to the Neogene and Quaternary. Reptiles include turtles (which are the most abundant), crocodiles, ichthyosaurs, sauropterygians, a basal lepidosauromorph, sphenodontians, a basal squamate, true squamate lizards, and snakes, from the Late Triassic to the Holocene. Localities are distributed in 21 Mexican states from which Sonora bears most records. Nineteen species based on Mexican fossils have been erected. Three have been considered invalid, one has changed taxonomic status, and at least two more are questioned. Most of the type specimens designated are housed in Mexican institutions. There have been 99 main non-redundant published documents that mention, list, or describe fossil amphibians and reptiles, including scientific papers, books and book chapters of international and national circulation, meeting abstracts, guidebooks and newsletters. Of all papers published, only 51 are formal publications in either national or international press and 40 were published in international journals or editorials. Mexicans have published only 10 international papers. However, Mexican paleoherpetology has significantly increased in the last two decades, although most information is hidden in gray literature of difficult access to the international community. It is imperative that Mexican workers document their discoveries in formal publications.