Corumbella and in situ Cloudina in association with thrombolites in the Ediacaran Itapucumi Group, Paraguay

Abstract

Terra Nova, 23, 382–389, 2011 Abstract An in situ assemblage of Cloudina, thrombolites and an ichnofossil (cf. Archaeonassa), together with fragments of Corumbella werneri, is reported here, from a tidally influenced, shallow, lagoonal setting on a carbonate ramp within the Itapucumi Group, Paraguay. The association of Cloudina with thrombolites is comparable to other terminal Neoproterozoic occurrences, but the coexistence of shelly fossils in situ with trace fossils and microbially induced sedimentary structures is apparently unique. This discovery extends the record of Cloudina and Corumbella in South America and further elucidates the diversity, distribution and palaeoecology of shelled organisms in late Ediacaran time.

Correlations of some Neoproterozoic carbonate-dominated successions in South America based on high-resolution chemostratigraphy

“…This succession is followed by ooid grainstones, microbialites, and dolostones of the Camba Jhopo and Tagatiyá Guazú formations, and capped by dolostones, marls, and pelites of the Cerro Curuzú Formation Warren 2011). Close to the Paraguay River, this unit has been metamorphosed in the lower-greenschist facies cratonic cover comprised by lagoonal facies deposited in inter-to supratidal context, associated with laminated microbialites and thrombolites containing Cloudina sp., Corumbella werneri, and simple ichnofossils (Boggiani & Gaucher, 2004;Warren et al 2011Warren et al , 2012. Covering these successions there are pelites, marls, and grainstones of the Cerro Curuzú Formation representing deep-shelf depositional systems with siliciclastic contribution Warren 2011).…”

“…Sial (2014, unpublished); (5) Misi et al (2007); (6) Alvarenga et al (2014); (7) Misi & Veizer (1998); (8) Torquato & Misi (1977); (9) Kaufman et al (2010); (10) Jacobsen & Kaufman (1999); (11) Warren et al (2011); (12) Mallmann et al (2007); (13) Oyhantçabal et al (2009); (14) Gaucher et al (2004, (15) Gaucher et al (2007); (16) Gómez Peral et al (2007); (17) Bagnoud- Velásquez et al (2013); (18) Gómez Peral et al (2014); (19) Boggiani et al (2010); (20) Santos et al, 2000, (21) Souza (2015), (22) Alvarenga et al (2010); (23) Chiglino et al (2015), (24) Fraga et al (2014) (25) Santana et al (2016), unpublished, (26) Babinski et al (2007), (27) carbonates in NW Canada, NW Namibia, and SW Brazil (Halverson et al 2007). Sr ratios of post-Sturtian and post-Marinoan carbonates led Babinski et al (2007) to question the use of Sr-isotope s...…”

O registro fossilífero de metazoários ediacaranos na América do Sul e suas implicações nos estudos sobre origem e complexificação da vida animal

“…É encontrada sob três modos principais de preservação, como coquinas, bioclastos finos ou conchas associadas com trombólitos. Essa última é a forma mais comum de preservação de Cloudina em outras localidades do planeta e indica os habitats desses organismos, uma vez que, quando encontrados associados com trombólitos, eles apresentam-se articulados e prostrados, com preservação in situ (Warren et al, 2011).…”

O registro fossilífero de metazoários ediacaranos na América do Sul e suas implicações nos estudos sobre origem e complexificação da vida animal

“…Em Corumbá, Corumbella ocorre na mesma formação que o fóssil Cloudina, porém, diferentemente deste, os fósseis de C. werneri não ocorrem em carbonato, mas em margas e folhelhos. Outros registros também foram observados nos arenitos de Great Basin (membro inferior da Formação Wood Canyon, EUA, Hagadorn e Waggoner, 2000) e nos grainstones e mudstones do Grupo Itapucumi (Paraguai, Warren et al, 2011;2012).…”