What is "pandoravirus"

Pandoravirus, first announced in a 2013 paper, is a genus of giant virus with the largest genome size and second largest physical size of any known viral genus. Like the other very large viruses Mimivirus, Pithovirus and Megavirus, Pandoravirus infects amoebas, but its genome, containing 1.9 to 2.5 megabases of DNA, is twice as large as that of Megavirus, and it differs greatly from the other large viruses in appearance and in genome structure.

Although the capsid of Pithovirus is 50% larger in size, Pandoravirus has the largest genome among all known viruses.