Octavio del Rio, an archaeologist, and colleague diver Peter Broger discovered the smashed skull and bones in a cave near where the Mexican government proposes to build a high-speed tourist railway through the forest.
Given the distance from the cave entrance, the skeleton couldn't have arrived without contemporary diving equipment, thus it must be over 8,000 years old, according to Del Rio, alluding to the period when increasing sea levels flooded the tunnels.
He stressed that the cave — whose location he did not reveal because of a fear the site could be looted or disturbed — was near where the government has cut down a swath of jungle to lay train tracks, and could be collapsed, contaminated or closed off by the building project and subsequent development.
Del Rio said the route through the jungle should be abandoned and the train should be built over the already-impacted coastal highway between Cancun and Tulum, as was originally planned.