Amoebozoans are believed to have existed for hundreds of millions of years. These ancient protists are characterized by the presence of pseudopodia, cytoplasm-filled projections that are used for locomotion and feeding. Today, over 2,000 species of Amoebozoa are recognized. The phylum itself was first scientifically described by Max Lühe, a professor at the University of Königsberg (Germany), in 1913. Dr. Leigh Anne Riedman, a NASA Astrobiology Postdoctoral Fellow at Harvard University (Department of Earth and Planetary Sciences), specializes in Precambrian paleontology.