ssRNA-RT viruses have their positive-sense genome transcribed by RdDp to synthesize a negative-sense complementary DNA (-cDNA) strand.

[7] After replication and translation, the genome and viral proteins are assembled into complete virions, which then leave the host cell.

[11] Phylogenetic analysis of RNA polymerases is used to study the evolutionary history of Riboviria because it is the only gene preserved among all ribovirians.

[3][12] More specifically, the two orders of the kingdom, Blubervirales and Ortervirales, appear to have evolved from two different retrotransposon families on two separate occasions by acquiring host proteins and using them for virion formation.

[14][15] The unclassified phylum Taraviricota may be such capsidless RNA ancestors as it appears to be the basal lineage from which all Orthornavirae phyla are descended from.

Viruses of the kingdom Shotokuvirae in the realm Monodnaviria appear to have come into existence on multiple, independent occasions.

[48][49] Coronaviruses and influenza viruses cause disease in various vertebrates, including bats, birds, and pigs.

[50][51] The family Retroviridae contains many viruses that cause leukemia, immunodeficiency, and other cancers and immune system-related diseases in animals.

Cucumber mosaic virus infects more than 1,200 plant species and likewise causes significant crop losses.

Brome mosaic virus is found throughout much of the world and primarily infects grasses, including cereals, though it does not cause significant economic losses.

[19][54] Many reverse-transcribing viruses in Riboviria integrate their genome into the DNA of their host by means of the retroviral enzyme integrase.

Endogenization is a form of horizontal gene transfer between unrelated organisms, and it is estimated that about 7–8% of the human genome consists of retroviral DNA.

[56] Viruses transmitted by arthropods have been central in the development of vector control, which often aims to prevent viral infections.

[57] In modern history, numerous disease outbreaks have been caused by various members of the realm, including coronaviruses, ebola, and influenza.

[58] HIV especially has had dramatic effects on society as it causes a sharp decline in life expectancy and significant stigma for infected persons.

With the development of viral metagenomics, many additional RNA viruses were identified, helping to fill in the gaps of their relations.

[12] This led to the establishment of Riboviria in 2018 to accommodate all RdRp-encoding RNA viruses based on phylogenetic analysis that they were related.

[3] When the realm was founded, it mistakenly included two viroid families, Avsunviroidae and Pospiviroidae, and the genus Deltavirus, which were removed in 2019 because they use host cell enzymes for replication and not RdRp or RdDp.

[13][62] These discoveries have mainly occurred in marine environments, where many novel lineages of microbial eukaryotic and prokaryotic RNA viruses have been discovered.

[13][63] The ecological role of these novel marine viruses is relatively unexplored, but they may be involved in the recycling of nutrients in a process called viral shunt.