Structural view of a<unk> <unk>  are caused by viruses in the<unk>  subfamily, a group of related RNA viruses that cause<unk>  in mammals and birds. In humans and birds, the group of viruses cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the common cold (which is also caused by other viruses, predominantly rhinoviruses), while more lethal varieties can cause SARS, MERS and COVID-19. As of 2021, 45 species are registered as<unk> es, whilst 11<unk>  have been identified, as listed below.<unk> es are known for their shape resembling a stellar corona, such as that of the Sun visible during a total solar eclipse; corona is derived from the Latin word , meaning 'garland, wreath, crown'. It was coined by Tony Waterson (professor of virology at St Thomas' Hospital) in a meeting with his colleagues June Almeida and David Tyrrell, the founding fathers of<unk>  studies, and was first used in a Nature article in 1968, with approval by the International Committee for the Nomenclature of Viruses three years later. The first<unk> was discovered in the late 1920s, however, the most recent common ancestor of<unk> es is estimated to have existed as recently as 8000 BCE. Human<unk> es were discovered in the 1960s, through a variety of experiments in the United States and the United Kingdom. A common origin in human<unk> es are bats.
Coronavirus diseases
Swine influenza
Spanish flu
Influenza
Influenza 
Bird Flu
Polymer fume fever
Virgin soil epidemic