JAVELINOXYLON, AN UPPER CRETACEOUS DICOTYLEDONOUS TREE FROM BIG-BEND NATIONAL-PARK, TEXAS, WITH PRESUMED MALVALEAN AFFINITIES

Well-preserved petrified woods from the Maastrichtian of Big Bend Nati onal Park, Texas, with a combination of characters seen in the Malvale s are described as Javelinoxylon multiporosum gen. et sp. nov. One log is over 70 cm in diameter and is riddled with termite galleries; this specimen provides additional documentation for the occurrence of dico tyledonous trees in the Late Cretaceous. These woods have structure di fferent from any other known Cretaceous dicotyledonous wood and are ad vanced in the Baileyan sense as vessel elements are relatively short, perforations are exclusively simple, vessels are commonly in long radi al multiples, and rays are storied. This is the earliest record for wo ods with storied structure. The occurrence of large dicotyledonous tre es with advanced wood structure in Big Bend suggests there were differ ences between the Late Cretaceous vegetation of the northern Rocky Mou ntains and the Big Bend region.