Infra red spectroscopy, flash pyrolysis, thermally assisted hydrolysis and methylation (THM) in the presence of tetramethylammonium hydroxide (TMAH) of cultured and sediment-derived Lingulodinium polyedrum (Dinoflagellata) cyst walls

► Unlike most other algae, but like pollen and spores, dinoflagellates have a diverse and long organic microfossil record. ► This is attributed to the unique composition of dinosporin, the dinoflagellate cyst wall material. ► Hithereto, attempts to unravel dinosporin composition have been unsuccessful or equivocal. ► We show that the walls of sediment- and culture-derived cysts of Lingulodinium machaerophorum are carbohydrate based. ► The material resembles cellulose but is more cross-linked, possibly explaining its fossilisation potential.