Fossiliferous sites of the southern coast of Rio Grande do Sul state, Brazil: geoheritage records of Quaternary sea-level, climate and environmental changes

The southern coastal plain of Rio Grande do Sul state hosts essential fossil records of both marine and terrestrial faunas that have provided invaluable information about the geological and environmental Quaternary history of southern Brazil. These fossils are found in surface and subsurface deposits on sites stretching from the continental shelf up to coastal lagoons inland. The sites on the shelf are time-averaged lag deposits formed of marine and terrestrial fossils exhumed and mixed together as a result of erosion of the original deposits by sea-level oscillations. Although lacking any precise stratigraphic context, the available numerical dates indicate Middle to late Pleistocene ages. Fossils removed from the shelf by waves today form large Konzentratt-Lagerstätten on the beach, called concheiros. The sites on continental areas occur in barrier-lagoon depositional systems, and include marine deposits formed under higher than present sea levels formed by Middle and late Pleistocene and Early-Middle Holocene marine transgressions. The fossiliferous sites with well-defined stratigraphic context encompass fluvial and aeolian (loess) deposits and paleosols associated with the Middle-late Pleistocene Santa Vitória Alloformation and Cordão Formation outcropping along Chuy Creek. Fossils of late Pleistocene terrestrial and Holocene marine organisms were collected from the bottom and marginal terraces of Mirim Lagoon. Although most sites are not directly under threat today, their wide distribution poses potential problems for protection. Current protection measures for the sites and associated fossils include requests by environmental agencies for preliminary surveys and fossil rescue programs prior to construction projects, and the proposal of a marine-coastal protected area is currently under consideration. Educational programs with schools and exhibits for the general public executed by the museums in the town of Santa Vitória do Palmar have contributed to public awareness about the importance of the regional paleontological heritage and have produced positive feedback and results that increased the number of known fossiliferous sites in the region thanks to communication by local people. These actions are essential to establish protection measures in case new developments emerge in the future that could threaten the sites and their fossils

A skull of the extinct tayassuid Brasiliochoerus stenocephalus (Lund in Reinhardt, 1880) (Mammalia, Cetartiodactyla) from the Late Pleistocene of southern Brazil: morphology and taxonomy

Among the several fossils of South American tayassuids, it is remarkable the presence of a well-preserved skull from southern Brazil (Chuí Creek, Santa Vitória do Palmar, Santa Vitória Formation). Here, we provide an update in the taxonomic arrangement and anatomical description of this specimen assigned to Brasiliochoerus stenocephalus based on the combination of the following traits: 1) long rostrum with a markedly convex profile; 2) anterior margin of the orbits located behind the vertical plane of the distal part of M3; 3) facial crests of the zygomatic arch forming an angle of about 80° relative to the molar series; 4) postorbital process more developed and ventrally projected in comparison to other tayassuids; 5) absence of a sagittal crest and presence of short parasagittal crests; 6) presence of curved temporal crests; 7) accentuated basicranial flexion; 8) bunodont and brachydont cheek teeth; 9) conspicuous pneumatization; 10) short postcanine diastema; and 11) cranium with no postorbital depression. This specimen was collected from sedimentary levels that contain a diverse assemblage of Pleistocene terrestrial mammals. Based on living analogous species, the presence of this taxon indicates dry and relatively open environments at some part of the Late Pleistocene in the study area.Fil: Copetti, Paula Lopes. Universidade Federal de Santa Maria; BrasilFil: Gasparini, Germán Mariano. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Pereira, Jamil Corrêa. Museu Coronel Tancredo Fernandes de Mello; BrasilFil: Fontoura, Emmanuelle. Universidade Federal de Santa Maria; BrasilFil: Lopes, Renato Pereira. Universidade Federal do Rio Grande do Sul; BrasilFil: Kerber, Leonardo. Universidade Federal de Santa Maria; Brasi