Biostratigraphical and palaeoecological implications of the small mammal assemblage from the late early Miocene of Montalvos2, Teruel Basin, Spain

Abstract

The rich early Miocene small mammal assemblage from Montalvos2, collected from lacustrine deposits directly overlying the basement, is unique within the Teruel Basin, a basin that is otherwise well known for its late Miocene/Pliocene mammal faunas. The presence of Democricetodon decipiens, Megacricetodon primitivus, Eumyarion and Ligerimys ellipticus enables correlation with the local biozone Ca (approx. 16.3 Ma, MN4). The high percentage of ochotonids in Montalvos2 is remarkable, a phenomenon that is known to occur in older assemblages from the adjacent Calatayud-Montalbán Basin. The association in Montalvos2 includes species indicative of an arid biotope, such as the ochotonid Lagopsis penai and the rodents Simplomys simplicidens, Armantomys aragonensis, Melissiodon dominans and the xerine squirrel Heteroxerus, and species that are supposed to have lived in a more humid forested biotope, such as the Talpidae and the flying squirrel Albanensia. This wide range of species indicates that the environment in the Teruel Basin was highly diverse during the early Miocene.