Description and controls on distribution of Pleistocene vertebrate fossils from the central and southern sectors of the Coastal Plain of Rio Grande do Sul, Brazil

Abstract

The objective of the present work is to compare the presence of Pleistocene vertebrate fossils from the central and southern sectors of the Coastal Plain of Rio Grande do Sul, quantifying and qualifying the taphonomy, and taxonomic group and skeletal remains representativeness. A total of 2,820 fossils was collected, among them 95% were collected in the southern sector and 5% in the central sector. In both sectors were identified two populations of bioclasts: non-identified fossils (85%) and identified fossils (15%). The same taxonomic groups and skeletal remains were identified in both sectors, except for some due to the different amount of fossils collected. The two populations of bioclasts identified represent greater (85% non-identified) or less (15% identified) reworking by waves. The hypothesis for the different amount of fossils collected is the availability of fossils on the shoreface and inner continental shelf. The presence of several submerged sedimentary rocks and records of paleolagoons and paleochannels on the shoreface and inner continental shelf of the southern sector indicates probably the source-areas where the skeletal remains were once fossilized and now are being eroded.

Ecological traits of the franciscana dolphin (Pontoporia blainvillei) from the Late Pleistocene to the present days based on stable isotope analysis

“…The source of the fossils are submarine deposits found at depths between 0 and 20 m of the shoreface, principally carbonate rocks and sandstones (Buchmann & Tomazelli, 2003;Buchmann et al, 2001) that are exposed and transported to the beach during strong storm waves produced by extratropical cyclones (Buchmann, 1994(Buchmann, , 2002Buchmann & Tomazelli, 2003;Buchmann et al, 2001;Cruz et al, 2016). Because the sea level was then more than 100 m below current levels (Rosa et al, 2017;Villwock & Tomazelli, 1995), and the continental shelf was occupied by terrestrial environments during glacial periods (Buchmann, 1994;Lopes & Buchmann, 2011), marine fossils are thus otherwise associated with interglacial periods.…”

Palaeoenvironmental dynamics of Holocene shoreface bryoliths from the southern coast of Brazil

“…The RSCP is characterized by several marine and continental fossil deposits located both on the continental shelf (Buchmann, 1994; Figueiredo, 1975) and in continental areas landwards of the present-day coastline (Lopes, 2013). On the inner shelf, predominantly Holocene mollusc shell deposits (Ritter et al, 2017) are exposed during autumn and winter erosive events by strong storm waves produced by the passage of extratropical cyclones and transported to the beach (Cruz et al, 2016).…”

Vertebrados e invertebrados fósiles en la Costa Atlántica de la Provincia de Buenos Aires, Argentina. Edad y paleoambientes

“…En contraposición, los fósiles de vertebrados e invertebrados depositados en las playas del sur de Brasil han recibido mayor atención, fundamentalmente a partir de los trabajos de Paula Couto (1975Couto ( , 1979 y Soliani y Jost (1974), y desde entonces se han sucedido una gran cantidad de estudios (e.g. Cunha, 1959;Paula Couto y Cunha, 1965;Figueiredo, 1975;Oliveira, 1992Oliveira, , 1996Buchmann, 1994Buchmann, , 2002Lopes et al, 2001Lopes et al, , 2008Lopes et al, , 2009Lopes et al, , 2013Lopes et al, , 2014Caron, 2004;Rodrigues et al, 2004;Lima y Buchmann, 2005;Scherer, 2005;Marcon, 2007;Lopes y Buchmann, 2010, 2011Lopes y Pereira, 2010;Lopes, 2013;Cruz y Buchmann, 2010;Lopes y Ferigolo, 2015;Cruz et al, , 2016. Al sur del estado de Río Grande do Sul, donde los hallazgos de restos faunísticos son muy frecuentes y forman acumulaciones junto con restos de conchillas fósiles y actuales se conforman grandes "konzentrat-lagerstätte", conocidos regionalmente como "Concheiros" (Lopes y Buchmann, 2010).…”

“…Al sur del estado de Río Grande do Sul, donde los hallazgos de restos faunísticos son muy frecuentes y forman acumulaciones junto con restos de conchillas fósiles y actuales se conforman grandes "konzentrat-lagerstätte", conocidos regionalmente como "Concheiros" (Lopes y Buchmann, 2010). En Brasil, esta mezcla de fósiles marinos y terrestres es atribuida a las oscilaciones del nivel del mar ocurridas a lo largo del Cuaternario (Cruz et al, 2016). Durante períodos glaciares, amplias áreas de plataformas continentales marinas quedaron expuestas y ocupadas por ambientes continentales, incluyendo cuerpos y cursos de agua, que favorecieron la preservación de restos fósiles de organismos terrestres.…”

“…Posteriormente, esas mismas áreas fueron inundadas por el mar, durante períodos interglaciares, y los restos fósiles enterrados fueron expuestos y retrabajados debido al ascenso del nivel del mar (Lopes y Buchmann, 2010;. Como resultado de varias de estas oscilaciones del nivel marino, restos fósiles de diversas procedencias fueron transportados y acumulados en las playas arenosas (Cruz et al, 2016), resultando en el hallazgo de vertebrados e invertebrados marinos y continentales entremezclados (Lopes y Buchmann, 2010;Cruz et al, 2016).…”