Volosky, DiegoDiegoVoloskyPhilippe Moisan TapiaLara, Maria BelenMaria BelenLaraSchneider, Joerg W.Joerg W.SchneiderScholze, FrankFrankScholzeEspinoza, MauricioMauricioEspinozaSchmitz, OlgaOlgaSchmitzAguilar, MaiteMaiteAguilarMorales, DanielaDanielaMoralesFlores, MarceloMarceloFloresContreras, JavierJavierContrerasFrenzel, PeterPeterFrenzel2026-07-062026-07-062025PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, 679, 113328 (2025). https://doi.org/10.1016/j.palaeo.2025.1133280031-0182https://hdl.handle.net/20.500.12740/24553Triassic sedimentary units are widespread in Chile, but the fossil record has been characterized mainly by macrofloral remains, with comparatively scarce evidence of other groups. We present the first description of a relatively complete Triassic continental paleoecosystem from the El Mono Formation of northern Chile. The El Mono Formation is a mainly siliciclastic continental unit deposited in a fluvial-lacustrine syn-rift setting during the initial stages of the Gondwana break-up, preserving a diverse fossil record largely unknown until now. The studied sections at the different localities are interpreted as lacustrine environments. The recorded biota represents the most complete continental Triassic paleoecosystem found to date in the Southwestern Gondwana margin, with a trophic chain spanning terrestrial producers, primary and secondary consumers of both continental and aquatic origin, and aquatic top predators. Recorded fossil organisms include macroflora, insects, conchostracans (clam shrimps), ostracods (seed shrimps), unionid bivalves, freshwater sharks, and bony fishes. The newly discovered biota, particularly insects and freshwater sharks and other fishes, represents a major advance for Chilean paleontology, shedding light on fossil groups that have remained largely unknown or unstudied. This unit also represents a promising target for basin analysis studies, as it records a relatively complete rift system evolution. Furthermore, it exhibits preservational features characterized by high concentrations of macrofloral remains and freshwater invertebrates, grouped fossilization of several organisms within single beds, and the preservation of delicate remains including insect wings and articulated fish skeletons. Accordingly, a Konservat-Lagersta<spacing diaeresis>tte designation for this fossiliferous unit is proposed here for the first time.PDFCreative Commons Attribution 4.0 International (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/Late TriassicPaleozoologyPaleobotanyMesozoic lagerstätteChileFRESH-WATER BIVALVESVILLA UNION BASINTRANSANTARCTIC MOUNTAINSLACUSTRINE SEDIMENTSCONVERGENT MARGINARGENTINAEVOLUTIONOSTRACODAVARVESREGIONArticlehttps://doi.org/10.1016/j.palaeo.2025.113328