"How can what did not erode for 100 million years to expose a full dino print , now be eroding only within the last 40 ?"
"Because the location of the tracks used to be a tidal plane . In other words , it used to be at the edge of the ocean . Around that time the sea coast advanced and receded several times . The tracks were buried . The tracks actually had to be uncovered . The tracks were originally discovered immdiately after an unusually severe storm in the area in which an unusual amount of water came down the Paluxy . That unusual flow of water washed away the soil that covered some of the tracks . Other tracks have been intentionally uncovered . For example , in one case , where a trackway went under a bank , several feet of the bank was removed to expose more tracks ."
"How can what did not erode for 100 million years to expose a full dino print , now be eroding only within the last 40 ?"
"Because the location of the tracks used to be a tidal plane . In other words , it used to be at the edge of the ocean"