Rodents from the Baynunah Formation

The Baynunah Formation of western Abu Dhabi Emirate includes the only record of late Miocene fossil mammals from the Arabian Peninsula. This study reports on new fossil rodents, recording three species previously unknown from the fauna. The first fossil squirrel from the Baynunah Formation is described here, although the limited material makes a detailed taxonomic assessment difficult. An additional indeterminate dendromurine species is also identified. Additionally, a new genus and species of an exceedingly large fossil gerbil, [gen et sp nov], is described. This species exhibits several primitive traits relative to the co-occurring Abudhabia baynunensis, yet is more derived than closely related (yet older) Ameuromys grandis. [gen et sp nov] most likely represents an intermediate species in the Ameuromys grandis — Abudhabia baynunensis group. The rodent fauna also supports previous biochronological estimates for the Baynunah Formation (8 to 6 Ma). The absence of leporids among the Baynunah micromammals suggests the fauna is older than 7 Ma. Lastly, although the Baynunah fauna shows a strong African biogeographic signal overall, the rodents represent a portion of the fauna with significant relationships with Asia.