More about Ancient Environments

This selection of fossil molluscs from a locality near Wanganui city is an assemblage typical of those found in soft, muddy seafloor environments. This seafloor is now represented by the fossil-bearing siltstones (‘papas’) exposed in the Whanganui cliffs, which represent the deepest-ocean conditions within cycles of fluctuating sea levels. The Whanganui area is now recognised as a globally significant site for studying past sea level and climate changes.

As well as determining ancient physical environments, paleoecology allows biological interactions between species to be inferred from the fossil record. This opens up understanding of ancient habitats and ecosystems. Some organisms leave distinctive trace fossils such as tracks and footprints as they feed, and certain marine gastropods generate unique feeding borings in the shells of prey species.

crab

The crab Tumidocarcinus was a likely predator of molluscs (©Ewan Fordyce)

crab

Chipping along the edges of this shell indicates that it was attacked by a crab (©Ewan Fordyce)