Group. Fossils of Miocochilius, the most abundant mammal at La Venta, were found alongside the primates Mohanamico hershkovitzi, Neosaimiri fieldsi and Stirtonia tatacoensis, the rodents Scleromys colombianus, S. schurmanni, Drytomomys aequatorialis, Neoreomys huilensis, Eodolichotis maddeni, Rhodanodolichotis antepridiana, Prodolichotis guerreroi and P. pridiana, the ant eater Neotamandua borealis, the bat Notonycteris magdalenensis, the pampatheriid Scirrotherium hondaensis, other notoungulates Pericotoxodon platignathus, Huilatherium pluripicatum, the sea cow Potamosiren magdalenensis, the sparassodonts Hondadelphys fieldsi and Lycopsis longirostrus, the litoptern Megadolodus molariformis and the ground sloth Magdalenabradys confusum. The assemblage also contained the crocodylians Purussaurus neivensis and Charactosuchus fieldsi, the caiman lizard Dracaena colombiana, and the turtles Geochelone and Podocnemis pritchardi. The fossils belong to the Xenastrapotherium kraglievichi-Granastrapotherium snorki assemblage at La Venta. Based on vegetational and grazer diversity analysis of the La Venta fauna, it has been suggested the ecosystem resembled more that of Africa and Asia than of the modern Neotropics. The Peruvian specimen was collected in a conglomerate, deposited in a storm-dominated coastal to fluvial environment, alternatively described as lacustrine and paludal, at the Fitzcarrald Arch in the Ucayali River basin of Amazonian Peru. Other mammals found in the same location were the toxodont Pericotoxodon cf. platignathus, glyptodonts Boreostemma and Parapropalaehoplophorus septentrionalis, the ground sloth Urumacotherium and rodent Drytomomys cf. aequatorialis. The Bolivian species M. federicoi was discovered in fluvial silty claystones of the Honda Group, dated on the basis of 40K/40Ar analysis at 12.83 ± 0.11 Ma and 11.96 ± 0.11 Ma. The fossil was accompanied by a large variety of rodents, sparassodonts, litopterns, notoungulates and the glyptodonts Hapalops angustipalatus, Hiskatherium saintandrei and Propalaehoplophorus andinus. In total, 30 different genera of mammals are described from the Quebrada Honda fauna, while 68 genera were described at La Venta. See also Allalmeia Campanorco Interatherium Protypotherium References Bibliography Typotheres Miocene mammals of South America Laventan Neogene Bolivia Fossils of Bolivia Neogene Colombia Fossils of Colombia Honda Group, Colombia Neogene Peru Fossils of Peru Fossil taxa described in 1953 Prehistoric placental genera