Upper Cretaceous aquatic plants from Northern Mexico

Two aquatic plant genera assignable to Decodon (Lythraceae) and Ceratophyllum (Ceratophyllaceae) are described based on reproductive structures collected from the Cerro del Pueblo Formation (late Campanian [73.5 ma]), Coahuila, Northeast Mexico. Decodon is represented by three small seeds with a pyramidal shape, rounded borders, and a concave ventral surface with a rectangular valve towards the center of the seed ventral surface. The Ceratophyllum spiny fruit has an ellipsoidal central body and two proximal long spines flanking a short pedicel opposite the stylar projection. These new reports confirm the presence of both genera in the Upper Cretaceous sediments of Northeastern Mexico, and add to our recognition of diversity within the widely distributed freshwater communities along the margin of the epicontinental sea. (C) 2008 Elsevier B.V. All rights reserved.