De la Rosa said there have only been initial tests to find the age of the prints and more tests will be carried out both in Mexico and at a laboratory in Bristol in Great Britain.
The oldest discovered footprints in the Western hemisphere are in Chile, and are believed to be 13,000 years old. There 6,000-year old footprints in the U.S. state of California, in Brazil and in Nicaragua.
The age of the Mexican footprints is dwarfed by those found in Africa. The oldest known hominid foot marks are in Laetoli, in Tanzania, and are believed to have been made 3.5 million years ago.
The Cuatro Cienegas footprints were discovered in May embedded in a white rock called travertine, it said in the news release.
Each footprint is 10 inches long and under an inch deep. They spread over a distance of 30 feet.
It is likely they were imprinted in mud and preserved by some rapid change in the environment, said Arturo Gonzalez, director of the Desert Museum, in the Coahuila state capital of Saltillo.
"There must have been a natural phenomenon to rapidly cover them so they were not rubbed out and were perfectly preserved," Gonzalez said.
Copyright 2006 The Associated Press. All rights reserved.