Fossilized angiosperm pollen
This 96-million-year-old fossilized angiosperm pollen clump of Phimopollenites striolata was extracted by careful processing of sediment from three sites in Minnesota’s Dakota Formation. Florida Museum of Natural History researchers found about 40 separate clumps in the pollen samples used for a study published in the Proceedings of the National Academy of Sciences Dec. 24 print edition. Each individual grain within the clump in this image measures approximately 14-by-19 microns. Clumping is generally found only in animal-pollinated flowering plants.