In genealogical linguistics, the term genus is used (following Matthew Dryer's work) to refer to a level of genealogical classification that is comparable across the world and whose time depth is not greater than 4000 years.
- "In the genealogical classification of languages, a genus is a group of languages whose relatedness is fairly obvious without systematic comparative analysis, and which even the most conservative "splitter" would accept." (Dryer 2005:584)
The plural of genus is genera.
Typical examples of genera are the subfamilies of Indo-European (Germanic, Slavic, Celtic, Romance). Some families are so close-knit that they constitute a single genus, e.g. Turkic, Mongolic, Athapaskan, Algonquian, Mayan, Arawakan, Cariban. See Dryer (2005) for a list of 2560 languages, arranged by family and genus.
- "First, the languages are grouped into genetic groups roughly comparable to the subfamilies of Indo-European, like Germanic and Romance. I refer to each of these groups as a genus (following a suggestion by Bill Croft), since they are rather analogous to the taxonomic level of genus in biology." (Dryer 1989:267)
- Dryer, Matthew S. 1989. Large linguistic areas and language sampling. Studies in Language 13.2:257-292.
- Dryer, Matthew S. 2005. Genealogical language list. In: Haspelmath, Martin & Dryer, Matthew S. & Gil, David & Comrie, Bernard (eds.) The World Atlas of Language Structures. Oxford: Oxford University Press, 584-644.