CONCLUSIONS

Acid treated assemblages of agglutinated foraminifera (ATAs) show patterns of species diversity that mimic those of the original dead assemblages (ODAs) and those of the living assemblages; all show a progression from low to high diversity with passage from marginal marine through shelf seas to deep sea.

There is a clear progression in the distribution of species and genera from marginal marine to deep sea but it is impossible to determine the precise controls on species distributions. ATAs sometimes show the localised effects of transport in which case species distributions are slightly broader than for their live counterparts. For instance, transport of marsh species onto adjacent tidal flats and vice versa. However, there is no evidence of widespread transport of agglutinated tests.

Although the genus Miliammina is confined to marginal marine environments in the study area, it occurs on the deep shelf sea off Antarctica so it is not exclusively an index of marginal marine environments.

As experimentally induced ATAs fill the no-analogue gap for modern environments (alternative 2), there is no need to invoke different ecological preferences for fossil taxa (alternative 1).

The data on species abundance, species diversity, distribution of species and genera with respect to environment and geography, provide comparative baselines for the interpretation of fossil agglutinated assemblages.