Abstract: Several species of mammals endemic to the late Miocene faunas of the Maremma region of Tuscany in Italy are known to have undergone a significant degree of morphological change during the time interval between the deposition of V-1 and V-2 horizons at Baccinello. This raises the interesting question of whether or notOreopithecus, which occurs in association with both V-1 and V-2 faunas, exhibits corresponding morphological change or taxonomic differentiation through time. Detailed comparisons of theOreopithecussample from Baccinello V-1 (and from the biostratigraphically equivalent sites of Ribolla, Casteani and Montemassi) with the type material ofO. bamboliifrom the site of Monte Bamboli, tentatively correlated with Baccinello V-2, indicate that there are no morphological or metrical differences by which to distinguish them. The recovery of a small sample ofOreopithecusspecimens from the Trasubbie River valley near Baccinello, derived from horizons stratigraphically above those yielding a V-1 fauna, allows, for the first time, direct comparisons of material from different strata within a single depositional basin. The material consists of a newly discovered partial mandible (IGF 4883V) from the F1 horizon, and four isolated teeth, a malar fragment, and a patella from the V-2 horizon. IGF 4883V is very similar toOreopithecusspecimens from Baccinello V-1, although it differs in having a more molariform P3and relatively larger cheek teeth. However, given the extent of variation inOreopithecus, and the fact that the mandible almost certainly belonged to a male individual, these minor differences do not seem to be significant, and are best interpreted as being due to intraspecific variation. This conclusion is further supported by comparisons with Baccinello V-2 specimens, which appear to be indistinguishable from the large sample of specimens from Baccinello V-1. Although the sample ofOreopithecusspecimens from horizons located above V-1 remains small, there is sufficient material to conclude that there is no evidence of morphological change or taxonomic differentiation inOreopithecusduring the time interval of about 2Ma between Baccinello V-1 and V-2.

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{{Explor lien
   |wiki=    Wicri/Santé
   |area=    EdenteV2
   |flux=    Istex
   |étape=   Curation
   |type=    RBID
   |clé=     ISTEX:20492A2F0FE8E84A3D0D7A6231DAA1E031520977
   |texte=   The taxonomic status and biochronological implications of new finds ofOreopithecus from Baccinello (Tuscany, Italy)
}}