3D shape analysis of grass silica short cell phytoliths: a new method for fossil classification and analysis of shape evolution.

Fossil grass silica short cell phytoliths (GSSCP) have been used to reconstruct the biogeography of Poaceae, untangle crop domestication history and detect past vegetation shifts. These inferences depend on accurately identifying the clade to which the fossils belong. Patterns of GSSCP shape and size variation across the family have not been established and current classification methods are subjective or based on a 2D view that ignores important 3D shape variation.