The La Venta middle Miocene neotropical biome

The La Venta Konzentrat-Lagerstätte documents the astonishing biodiversity of one of the most fascinating neotropical biomes, through its abundant fossil concentrations. Its variegated fine- to medium-grained rock succession, part of the Honda Group, accumulated in dynamic fluvial and alluvial environments between ~15.9 Ma and ~10.5 Ma (Kay et al., 1997; Spradley et al., 2019; Carrillo, 2023).
In addition to plant remains and ichnofossils, over 190 different fossil taxa have been identified, including 50 new genera and 102 new species. The fossil fish assemblage documents the establishment of the rich extant fauna of the Orinoco and Amazon River basins, and the reptilian fossil remains give evidence of specialized adaptations. The Laventan mammalian fauna consists of 34 new fossil species of rodents, primates, bats, and sirenians, 26 new species of extinct native ungulates and xenarthrans, and 20 new taxa of oldest representatives of some extant metatherians (Kay et al., 1997; Defler, 2019; Carrillo, 2023).
Its emblematic “badlands” scenery and the development of excellent outcrops over an extensive area, results from the interplay between lithology, long-term weathering, and the dry conditions induced by the orographic rain shadow of Los Andes (Dill et al., 2020; Montes et al., 2021).