The mammal faunas from the upper Eocene and lower Oligocene from four localities in the Sierra Palomera (province of Teruel, Spain) are described: Villarrosano 1, 12, 14, and Aguatón. Two new species of rodents, Treposciurus manentis (Pseudosciuridae) and Bransatoglis attenuatus (Gliridae), are described from Aguatón. Comparison of the associations from the Sierra Palomera with the European standard succession (MP zonation) suggests a late Eocene age (MP 19–20) for Villarrosano 1 and Villarrosano 12 and a early Oligocene age for Aguatón and Villarrosano 14 (MP 21). The dental morphology and the relative abundance of the different mammal taxa from Villarrosano 1 and Aguatón suggest a more open environment in upper Eocene than in the early lower Oligocene in this basin.