México (Baja California Sur): Three weeks (5–24 July, 2004), funded by the NSF REVSYS grant. AMNH Ph.D. student, Edmundo González, REVSYS collaborators Dr Oscar Francke, Instituto de Biología, Universidad Nacional Autonoma de México (UNAM), and Warren Savary, California Academy of Sciences, and Alejandro Valdez, an undergraduate student and amateur speleologist from the Facultad de Ciencias, UNAM, travelled ca. 6,000 km, from Nayarit on the Mexican mainland, throughout the desert and oak forests of Baja California Sur. This trip included a mule ride to the pine forest on top of Sierra de La Laguna to collect endemic vaejovid scorpions for the REVSYS project. Collectively, ca. 2,370 specimens where collected in three arachnid orders (Amblypygi, Scorpionida, Solifugae). Six families, 12 genera and 31 species of scorpions were collected, including a new Paruroctonus and two new Vaejovis species.