First occurrence of Cloudina carinata Cortijo et al., 2010 in South America, Tamengo Formation, Corumbá Group, upper Ediacaran of Midwestern
Primera cita de Cloudina carinata Cortijo et al., 2010 en Sudamérica, Formación de Tamengo, Grupo de Corumbá, Brasil Brazil

R.R. Adôrno^1,2, D.H.G. Walde¹, B.D. Erdtmann³, M. Denezine¹, I. Cortijo⁴, D.A. Do Carmo¹, M. Giorgioni¹, M.E.A.F. Ramos¹, G. Fazio¹

¹University of Brasília, Institute of Geosciences, Campus Darcy Ribeiro, DF 70.910-900 Brasília, Brazil. Email: rodrigo.adorno@cprm.gov.br; ORCID ID: https://orcid.org/0000-0003-1781-0694, http://orcid.org/0000-0001-5324-5480, http://orcid.org/0000-0003-4629-0907, http://orcid.org/0000-0002-1613-7242, http://orcid.org/0000-0003-0565-3150, http://orcid.org/0000-0002-1741-3210, http://orcid.org/0000-0003-3325-5096

²Geological Survey of Brazil – Center for Technological Development-CEDES Setor Bancário Norte, DF 70040-904 Brasília, Brazil.

³Freie Universität Berlin (FUB). Kaiserswerther Street 16-18, 14195 Berlin, Germany. https://orcid.org/0000-0002-0136-7854

⁴Área de Paleontología, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas s/n, 06071 Badajoz, España. http://orcid.org/0000-0002-6027-9002

IntroductionTOP

This work deals with the unprecedented occurrence of Cloudina carinata Cortijo et al., 2010 in the American continent. C. carinata had documented occurrences in Spain (Cortino et al., 2010, 2015) and Siberia, Russia (Kontorovich et al., 2008), and now a new occurrence from the Tamengo Formation at Porto Figueiras section, Corumbá Municipality, Mato Grosso do Sul State, Brazil is presented.

Cloudina species have wide geographic distribution reported from Namibia (Grant, 1990), Oman (Conway Morris et al., 1990) , South China (Hua et al., 2005; Cai et al., 2013; Cortijo et al., 2015), Spain (Cortijo et al., 2010, 2015), Siberia (Terleev et al., 2011; Kontorovich et al., 2008); Mexico (Sour-Tovar et al., 2007), Brazil (Adôrno et al., 2017), Argentina and Uruguay (Gaucher et al., 2006), Canada (Hofmann & Mountjoy, 2001), Paraguay (Warren et al., 2011, 2013, 2014, 2017, 2019) and the USA (Grant, 1990; Zhuravlev et al., 2012).

Cloudina carinata occurs in the uppermost Ediacaran section of Spain, in association with C. lucianoi (Beurlen & Sommer, 1957) in the Membrillar olistostrome (Cortijo et al., 2010) and the Navalpino Anticline, central Spain (Cortijo et al., 2015). Occurrences of Cloudina carinata and C. lucianoi have also been reported from Siberia, Russia (Terleev et al., 2011), and now it is herein presented the first occurrence of this species in South America from the yellowish siltstones of the Tamengo Formation.

ResultsTOP

A new occurrence of Cloudina carinata is presented herein, in the Porto Filgueiras section, outcropping along the Paraguay river bank in a locality nowadays called Marina do Gelson, at the geographic coordinates: -18.998748° S and -57.629023°W, approximately 750 m to the west of the Sobramil Port section. At this locality, C. carinata occurs in association with C. lucianoi and Corumbella werneri. The implication of this new occurrence of C. carinata in the Tamengo Formation is discussed herein under the light of its contribution to the palaeobiogeographic distribution of Cloudina species, the palaeogeography of Western Gondwana, the palaeoecology and the chronobiostratigraphy of the uppermost Ediaracan sections.

The study material consists of silty impression moulds of the exterior wall of Cloudina carinata (Fig. 1). The taxonomic assignment of C.carinata from the Tamengo Formation is the result of morphometric and morphologic analysis. Regarding the mode of occurrence, C. carinata and Corumbella werneri occur in pelitic layers of the Tamengo Formation, while C. lucianoi occurs in carbonate rocks. This could reflect, to a certain extent, that C.lucianoi preferred palaeoecological conditions with clear waters and without major siliciclastic input, where carbonate could precipitate, whereas C. carinata and Corumbella werneri dwelled in probably deeper and calmer conditions, with more detrital influx. The occurrence of Cloudina carinata in the Tamengo Formation increases the potential for the inclusion of the Tamengo Formation in the international biostratigraphic correlation.

ConclusionsTOP

It is herein reported the first occurrence of Cloudina carinata in the American continent, from the Tamengo Formation in the Porto Figueiras section (Corumbá Municipality, Mato Grosso do Sul State, Brazil). The importance of this new occurrence is the expansion of the geographic distribution of Cloudina carinata, indispensable for global correlations. Additionally, this new occurrence could collaborate to the inclusion of the South America sections in international biostratigraphic correlation and palaeobiogeographic and palaeoecological reconstructions.

ReferencesTOP