The occurrence of the fossil genus Graminidites in the Maastrichtian Scollard Formation, Alberta, Canada, and its palaeoecological and palaeogeographical significance

Abstract

Fossil grass pollen is common in Late Tertiary sediments and its rare occurrence in the Early Tertiary led to the belief that its presence is restricted to Tertiary sediments. A literature survey shows that rare occurrences of Graminidites spp. have been reported from Campanian-Maastrichtian strata worldwide. All reported Graminidites spp. have been studied by transmitted light microscopes, which are inadequate to resolve their fine exine sculpture. Graminidites sp. occurs in the Maastrichtian Scollard Formation of Alberta, Canada, and is studied here with light microscopy and scanning electron microscopy. A new species, G.ulkapites, occurs at the initiation of a temperate climate in the area. It occurs in post-dinosaurian beds locally but in pre-Cretaceous-Tertiary boundary strata, which implies that grasses could also be present in dinosaur inhabitations. Grass phytoliths, reported from dinosaurian coprolites from the Maastrichtian Deccan Intertrappean sediments of India, indicate that grasses were ingested by dinosaurs even if not included in the dinosaurian diet. A plot of worldwide Senonian occurrences of Graminidites spp. on a late Maastrichtian palaeogeographic map demonstrates that the data are inadequate to reveal the place of origin or migratory pattern. © 2011 The Linnean Society of London.