Keywords: TrigonidBivalve.jpg en Trigonia sp from the Glen Rose Formation Cretaceous near Austin Texas Scale bar is 10 mm Own Wilson44691 Photograph taken by Mark A Wilson Department of Geology The College of Wooster http //www3 wooster edu/geology/MWilson html 2008-08-19 Trigonia fossils Fossils of Texas Cretaceous fossils from the United States Trigonia mollusca Bivalves with black background |