The ancient Térapa fossil site in northcentral Sonora, Mexico, "was covered with forest and grassland habitats that extended northward into Mexico by about 350 km relative to their present-day northern limits during the Late Pleistocene." The in-press report in the journal Palaeogeography, Palaeoclimatology, Palaeoecology is co-authored by UA scientist Arturo Baez.
Ref: Ancient forests and grasslands in the desert: Diet and habitat of Late Pleistocene mammals from Northcentral Sonora, Mexico, Elvis E. Nuneza, Bruce J. Macfadden, Jim I. Mead and Arturo Baez, doi:10.1016/j.palaeo.2010.08.021