Hepatitis D is one of the more widely-known satellite viruses, and it needs hepatitis B as the helper virus. that it required a coinfection was discovered in 2009
green algae โ Depending on how you define 'plant', green algae are sometimes lumped in with land plants, and other times considered to be a disconnected eukaryote. However, recent evidence shows that land plants evolved from green algae. [1][2][3][4]