Abstract
The Murinae represent the largest subfamily of mammals, comprising 656 species and 135 genera1. This groupof rodents constitutes one of the most evolutionarily successful clades of mammals, displaying an outstandingdiversity, a virtually cosmopolitan distribution and a wide array of feeding preferences. They supposedly originatedin the Middle Miocene of southern Asia, as their earliest representatives (Antemus) have been recordedin Siwaliks deposits about 14 Ma of age2–4. However, the full development of the dental pattern seen in modernmurines (with three strong chevrons in the M1) was achieved later, with the appearance of Progonomys inLate Miocene deposits of the same area dating 12.4 Ma2–4. Progonomys is probably one of the most importanttaxa in the history of murine rodents, not only because it was the earliest taxon to acquire the derived dentalcharacters of the crown murines, but also because it was the first modern representative of the group to spreadout of southern Asia. Progonomys dispersed from southern Asia to Europe and Africa at the beginning of theLate Miocene (~11 Ma). This dispersal and that of the three-toed horse Hipparion are seen as the two mostremarkable Late Miocene events in the history of Old World mammals5. The possible routes and timing ofthis first murine dispersal have been the subject of hypotheses6–8, which have remained educated guesses inthe absence of data from the Arabian area. Fossil material collected during excavations in the summer of 2013and 2018 in the Upper Miocene of Lebanon provides an opportunity to address this gap in our knowledge.Our fieldworks resulted indeed in the discovery of the first Progonomys from the whole Arabian area, whichconstitutes the first physical evidence about the dispersal of the earliest murines from southern Asia to Africathrough the Levant.