Cells come in many different shapes and sizes, and they can even be huge. Xenophyophores can grow to be up to 20 centimeters! They are not easy to investigate because they are so fragile, so scientists don't know a whole lot about them. They have been classified as protists, which is not exactly a descriptive classification, it means scientists have not been able to call them a plant, animal or fungus. You can hear more about their classification history from the video.
The video also describes another important feature of these big cells; they have thousands of nuclei (and are thus called multinucleates). That makes it easier for them to survive even though they are quite large, and have to engage in a lot of different functions, unlike multicellular organisms, which rely on specialized cell types to carry out the various required functions.
They are intriguing organisms. They have been found in the deepest place on earth, the Mariana Trench, and xenophyophores are likely the largest single-celled organism.
