Occurrence of dispersed seed cuticles and similar microfossils in mainly Cretaceous successions of the Northern Hemisphere

Species of the microfossil genera Carpotheca Binda & Nambudiri, Corniformitheca Knobloch, Costatheca Hall and Spermatites Miner are commonly encountered in marine basin margin and non-marine deposits of late Early and Late Cretaceous age in North America, Greenland, Europe and parts of North Africa. Their possible affinities have been the subject of discussion since they were first encountered. The morphological characteristics of most specimens referable to Carpotheca, Corniformitheca and Spermatites leave little doubt that they are seed cuticles. The possibility that some of those attributable to Costatheca might be insect eggs cannot, however, be dismissed. There are a few records of seed cuticles from older successions and all of these have been attributed to Spermatites , although they differ somewhat in character from Miner's concept of this genus. It is likely that they are derived from a heterogeneous group of gymnospermous plants unrelated to those to which many of the younger taxa belong. There is limited circumstantial evidence to suggest that at least some of the latter have angiospermous origins, their diversification, which is demonstrated on range charts, coinciding with the radiation of the flowering plants during the Late Cretaceous. Stratigraphic and occurrence data are documented in this paper along with bibliographic details, including page, plate and figure references, for all of the published Cretaceous and the very few younger records of these taxa. They suggest that seed cuticles and similar bodies may have greater potential as an aid to resolving biostratigraphic and palaeoenvironmental problems than has hitherto been realized.