Estimated time range of diversification of rat and mouse

Range 11e+6 - 12.3e+6 years
Organism Mammals
Reference Donoghue PC, Benton MJ. Rocks and clocks: calibrating the Tree of Life using fossils and molecules. Trends Ecol Evol. 2007 Aug22(8):424-31. Graph - link PubMed ID17573149
Primary Source Database - link
Method The extinct genus Karnimata (11.1 - 6.4 Ma) is interpreted as a member of the lineage leading to Rattus. The oldest record (11.1 Ma) is uncertain, but the next (at 10.4 Ma) is unquestionable. The early species, Progonomys hussaini (11.5 - 11.1 Ma) is interpreted as an undifferentiated basal murine antedating the common ancestor of Mus and Rattus by Jacobs and Flynn (2005), and so they place the Progonomys-Karnimata split (equivalent to the Mus-Rattus split) at not much beyond 11 Ma, ‘although it may be younger’. The dating is based on detailed field stratigraphic study of the long Siwaliks sedimentary sequence, with dating from magnestostratigraphy and radiometric dating (Johnson et al. 1985 Barry et al. 2002). The soft maximum constraint on this date is taken as the oldest record of Progonomys at 12.3 Ma.
Comments The 12 Ma figure has most commonly been selected as the mouse-rat calibration point, but dates in the range from 16 - 8.8 Ma have been used in recent molecular studies. For full discussion and references see link
Entered by Uri M
ID 105151