Mark David Protosevich (born August 24, 1961) is an American screenwriter. He wrote the screenplays for the films Poseidon and I Am Legend.Protosevich was born in Chicago, Illinois and is an alumnus of Columbia College Chicago.Protosevich also wrote the script for the unproduced Batman Triumphant. In 2011, Steven Spielberg met with Protosevich to discuss story ideas for Jurassic Park IV.