Formed 100,000,000 years ago, tracks of 3 kinds of dinosaurs are preserved in the limestone below Paluxy River. Types include Acrocanthosaurus (a meat-eater), Camptosaurus (plant-eater who left 3-toed bird-like tracks), and Pleurocoelus (a plant-eater who made huge 5-toed prints). For years following their discovery (about 1910), the tracks remained a novelty. When Paluxy River ran low, farmers caught catfish stranded in them. Excavations by a prominent museum and several universities in 1938 brought the tracks to the attention of the world. (1970)