The rangeomorph : Hydrodynamic function at the dawn of animal life.

Rangeomorphs are among the oldest putative eumetazoans known from the fossil record. Establishing how they fed is thus key to understanding the structure and function of the earliest animal ecosystems. Here, we use computational fluid dynamics to test hypothesized feeding modes for the fence-like rangeomorph , comparing this to the morphologically similar extant carnivorous sponge .