A fossil dicotyledonous woodland/forest from the Upper Cretaceous of Big Bend National Park, Texas

A fossil woodland/forest in Upper Cretaceous strata of the Aguja Formation in Big Bend National Path, Texas, preserves two species of dicotyledonous t rees with trunks up to 1.3 m in diameter. The straight buttressed trunks, a bsence of low branching, and lack of distinct growth rings suggest that the se trees represent a tropical evergreen community having a canopy height of 40 to 50 m. Well before the end of Cretaceous time, dicotyledonous angiosp erms were the dominant canopy forming trees in at Least some ecosystems ing rowth America. These trees may have been among the woody plants that produc ed the Normapolles palynoflora.