Hu, Shusheng , Taylor, David W. .
Pollen clumps and implications on the coevolution of early angiosperms and their pollinators.
Fossil angiosperm pollen clumps could have had either a floral or zoological origin. Studies of modern pollination biology suggest the evolution of floral pollen clumps is due to insect pollination and that sticky pollen might be ancestral in angiosperms. We made a preliminary study on pollen samples from the Aptian to the Campanian of the USA to examine the frequency of pollinator modes based on dispersed pollen and to track the presence of clumps. Angiosperm pollen clumps are not found in the Aptian sediments. In contrast, twelve types of pollen clumps are recovered from the Campanian sediments. We described these clumps and developed criteria to distinguish between floral clumps and fecal pellets. Floral clumps are irregularly shaped with rough edges and composed of a single species of pollen grains that are well preserved. Floral clumps appear rare until the mid-Cretaceous. The distribution of clumps suggests that the pollen from early angiosperm flowers were not sticky and that stickiness may have evolved with adaptation to more advance pollinators. Fecal pellets are regularly shaped with smooth margins and the grains show damage. Based on the presence of different types fecal pellets it seems likely that a number of digestive strategies were in place and likely used by members of Coleoptera, Diptera and Hymenoptera.
Log in to add this item to your schedule
1 - Yale University, Peabody Museum of Natural History, 170 Whitney Ave., New Haven, CT, 06511
2 - Indiana University Southeast, Department of Biology, 4201 Grant Line Road, New Albany, IN, 47150
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Superior A/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 11:15 AM