When you think of bacteria, you assume that they can only be seen under a microscope. They are single-cell organisms, after all. But scientists have discovered one that can can grow up to two centimeters (.78 inches) long! Yes, that is still only one cell. Thiomargarita magnifica is not the first known bacteria that can be seen with the naked eye, but it is the biggest so far, ten times bigger than scientists thought possible. But that's not all that makes T. magnifica special.
Most bacteria contain DNA free-floating in the cell, while higher orders of life package and protect their DNA in a cell nucleus. But T. magnifica separates its DNA in a sac, separate from a water-filled sac that it uses to take in nutrients. That difference blurs the line between bacteria and other single-cell microbes (prokaryotes) and multi-cellular species (eukaryotes). We may have to redefine classifications due to this new discovery. Read about Thiomargarita magnifica and how it was discovered at Science.