Assinaturas tafonômicas em moluscos recentes e seu significado paleoambiental

Erthal, Fernando; Ritter, Matias do Nascimento; Kotzian, Carla Bender

doi:10.20396/td.v13i1.8648624

Cited by 10 publications

(5 citation statements)

References 130 publications

(221 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A aquisição e descrição dessas assinaturas teve como base Kidwell et al (1986), Davies et al (1988), Best e Kidwell (2000a, b), Simões e Ghilardi 2000e Kidwell et al (2001). O método empregado foi adaptado a partir de análises tafonômicas aplicadas em conchas de depósitos paleolagunares análogos aos estudados aqui (Erthal, 2012;Ritter et al, 2013;Pereira, 2016). Figura 36.…”

Section: Análise Tafonômicaunclassified

O registro climático e ambiental das conchas de sambaquis e depósitos paleolagunares na costa centro-sul Catarinense

Casati¹

View full text Add to dashboard Cite

show abstract

Section: Análise Tafonômicaunclassified

O registro climático e ambiental das conchas de sambaquis e depósitos paleolagunares na costa centro-sul Catarinense

Casati¹

View full text Add to dashboard Cite

show abstract

“…The shells include from complete to fragmented and highly abraded specimens exhibiting varied colors ranging from white, yellow, reddish, and dark gray or black (Fig. 5A), and may show encrustation by barnacles, bryozoans and polychaetes, besides traces of bioerosion by invertebrate predators and parasites (Lopes and Buchmann 2008;Erthal 2012;Lopes 2012;Ritter et al 2019). Other fossils of marine invertebrate species include echinoderms (Fig.…”

Section: The Fossil Assemblages Of the Shelf And Concheirosmentioning

confidence: 99%

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

Lopes,

Pereira,

Ritter

et al. 2024

JGSB

View full text Add to dashboard Cite

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.

show abstract

“…Shells from these relict deposits initially yielded 14 C ages ranging from 14,580 years BP to more than 30,000 years BP (Figueiredo 1975, fide Erthal 2012). AMS 14 C dates (Ritter et al 2017) of the shallower deposits showed that 97% of the shells were younger than 6,000 years (median=1215 years).…”

Section: Geographical and Geological Settingmentioning

confidence: 99%

“…They found that discoloration correlated with postmortem age. Erthal (2012) and Ritter et al (2017Ritter et al ( , 2019 incorporated color, among other taphonomic attributes, as evidence of diagenesis on the Brazilian shelf. Erthal (2012) found a correlation between light colors (white, cream) and the presence of mud, and more loosely, between reddish colors and deposits abundant in heavy minerals.…”

Section: Introductionmentioning

confidence: 99%

“…Erthal (2012) and Ritter et al (2017Ritter et al ( , 2019 incorporated color, among other taphonomic attributes, as evidence of diagenesis on the Brazilian shelf. Erthal (2012) found a correlation between light colors (white, cream) and the presence of mud, and more loosely, between reddish colors and deposits abundant in heavy minerals. Ritter et al (2017) observed the highest color alteration in the shallowest sample of their study, and Ritter et al (2019) noted an increase in the frequency of shells with ocher, yellow, and red colors with depth.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Millenial-Scale Time Averaging Inferred by Discolored Shells in Beach Death Assemblages

Martínez

Rojas

2023

Palaios

View full text Add to dashboard Cite

Molluscan death assemblages occurring on present-day beaches frequently consist of secondary-colored shells, with yellow to brown and gray to black colors. It is hypothesized that this secondary coloration can be related to postmortem age and to conditions in the taphonomically active zone, altering shells to black and gray tones in reducing conditions, and then becoming yellowish or brownish in oxidizing settings. In this study, we assessed whether the variability in the degree of shell discoloration of two species of the infaunal bivalve Mactra collected in beach death assemblages from a temperate siliciclastic beach in Uruguay is a function of postmortem age, and whether this variability in discoloration can be linked to differences in their elemental composition, microstructure, and provenance. Although we did not detect any differences in mineralogy or elemental composition among shells differing in discoloration, we show that modern (younger than a century) beach shells are not secondary-colored, but have remained white, but some white shells are also old (millennial). In contrast, yellow and gray shells are consistently older than 1,000 years, indicating that this degree of discoloration requires millennial residence times in the taphonomically active zone and suggesting that discoloration can be used as an indicator of time averaging. Discolored shells are derived from subtidal death assemblages.

show abstract

Assinaturas tafonômicas em moluscos recentes e seu significado paleoambiental

Cited by 10 publications

References 130 publications

O registro climático e ambiental das conchas de sambaquis e depósitos paleolagunares na costa centro-sul Catarinense

O registro climático e ambiental das conchas de sambaquis e depósitos paleolagunares na costa centro-sul Catarinense

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

Millenial-Scale Time Averaging Inferred by Discolored Shells in Beach Death Assemblages

Contact Info

Product

Resources

About