1937 saw the discovery of the first coronavirus, the avian infectious bronchitis virus.
Investigators found that rhinovirus was only responsible for about one half of all common colds, so in 1960 they were able to isolage a human coronavirus from the nose. Today OC34 and 229E, are the two best know human coronaviruses and are believed to cause about 30% of common colds.
Made more famous in late 2002 by the severe acute respiratory syndrome (SARS) outbreak. Virus was sequenced and found to be most like coronaviri. However, it was not close enough to be put in with other known coronaviri and was put in a category on its own.
Coronaviruses are unusual viri. They have a large genome of about 30,000 base pairs. They are large viri. Most viris have a single gene, however, coronaviri have about ten.
Becaue coronaviri are large, it is felt that the develop from a recombination of two different viri, in the case of SARS, the two parent viri are unknown. Whether SARS developed in this fashion is unkown, another possibility is that it has existed for a long time in an animal resevoir and has now made the jump to humans.