ÒGregarious suspension feeding in the Ediacaran organism ErniettaÓ Authors: Brandt M. Gibson, Imran A. Rahman, Katie Maloney, Rachel A. Racicot, Helke Mocke, Marc Laflamme, and Simon A.F. Darroch Computational fluid dynamics (CFD) simulations were performed in COMSOL Multiphysics 5.4 to test between competing feeding models for the Ediacaran taxon Ernietta. In addition, we perform simulations for multiple individuals, allowing us to analyze hydrodynamics of living communities. All models were fixed to the lower surface of a cube. An inlet with a normal inflow velocity boundary condition was assigned to one end of the domain, with a zero-pressure boundary condition assigned to the opposing end. Slip boundary conditions were assigned to the top and sides of the domain, allowing inviscid flow along the walls, and a no-slip boundary condition was assigned to the lower surface of the domain and the surfaces of the fossil, fixing the fluid velocity at zero. The fluid properties of water (density = 1000 kg/m3; dynamic viscosity [?] = 0.001 kg/s*m) were assigned to the model for incompressible flow. The domain was meshed using free tetrahedral elements, which varied in size according to the distance from the fossil (larger elements used in regions further away from the fossil). Simulations were run using the shear stress transport turbulence model, which solves the Reynolds-averaged Navier-Stokes equations, and a stationary solver was used to compute the steady-state flow patterns.