PaleoBios

The Early to Middle Miocene mammal assemblage of the Castilletes Formation, Colombia records a diverse assemblage of mammals in the northern Neotropics prior to the Great American Biotic Interchange. We identify new records of herbivorous mammal taxa, with additional specimens of Huilatherium sp. and the first records of cf. Pericotoxodon sp., Miocochilius cf. M . anomopodus and ‘ Scleromys’ sp. All these genera are shared with other tropical Middle Miocene assemblages, including La Venta (Colombia) and Fitzcarrald (Peru) and increase the faunal similarity among them. Ecometric analysis of dental traits suggests a habitat change between the assemblages of the Castilletes Formation and the Ware Formation (Late Pliocene), consistent with results from other proxies that show increased opening and drying. In combination, these results support the utility of ecometric methods in Neogene South America and emphasise the importance of taxonomic revisions for these taxon-independent methods.