THE PALEOECOLOGICAL IMPLICATIONS OF THE CHAROPHYTE FLORA OF THE TRINITY DIVISION, JUNCTION, TEXAS

The Trinity Division exposures at Junction, Kimble County, Texas, yiel d a rich charophyte flora dominated by clavatoraceans. The presence of Atopochara trivolvis ssp. trivolvis (Peck, 1938) Grambast, 1968, and Clypeator corrugatus (Peck, 1941) Grambast, 1962, indicates an Aptian age for these strata and makes them the continental equivalent of the Lower Glen Rose. Atopochara trivolvis, whose type-material was recover ed from the Trinity in a deep well in southern Texas, is known from nu merous freshwater to oligohaline lakes from the Mesogean area in Europ e and Nor-th Africa as well as from Cretaceous oil-bearing basins in C hina. Charophytes are clear indicators of supratidal environments and the abundant remains at Junction suggest a positive structural feature in this part of central Texas that might have been either an island o r directly connected to the Llano Uplift.