eumalacostracan adjective 1noun 1forms 1 adjective1 •Characteristic of crustacea of the subclass Eumalacostraca.The diversity of crustaceans testifies to a dramatic Lower Carboniferous eumalacostracan radiation. — 2015 noun1 •Any crustacean of the subclass Eumalacostraca. formseumalacostracans
