Evidence of pteridophyte-arthropod interactions in the fossil record

The past decade has seen the emergence of considerable fossil evidence of a history of pteridophyte-arthropod interaction extending back to the Devonian period. Such fossils include plant tissue showing lesions, bites and borings with associated features implicating arthropods as causal agents. Gut contents of Carboniferous arthropods, which include lycopod xylem elements and spores, are a tangible demonstration of phytophagy. Pteridophyte spores in fossil droppings (coprolites) indicate the prevalence of arthropod spore-eating in the Palaeozoic. This may have had compensations for the source plant and evidently represented the start of the co-evolution which culminated in the elaborate adaptations shown by flowering plants and their insect pollination vectors

Carbon-13 solid state nuclear magnetic resonance of sporopollenins from modern and fossil plants

13C solid-state nuclear magnetic resonance (NMR) has been applied to modern pollen and spore exines (Betula, Pinus and Lycopodium) and those of two fossil spores (Lagenicula and Parka) in order to assess the composition of their constituent sporopollenin. While they prove to have broadly similar structural characteristics, there are some significant differences between all types and and particularly between the fossil and living material. The capacity of NMR to to demonstrate variation in structure, in what is clearly a heterogeneous group of organic macromolecules, suggests the possibility that this procedure could be of use in characterizing the sporopollenin of different plant groups. The fact that such material retains its structural integrity in the fossil state further opens up the possibility of our following evolutionary changes through time of this inert biomacromolecules