Megafossils from the Mesoproterozoic Rohtas Formation (the Vindhyan Supergroup), Katni area, central India

Kumar, Sanjeev

doi:10.1016/0301-9268(94)00085-6

Cited by 61 publications

(31 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1.6 Ga (Rasmussen et al, 2002;Ray et al, 2002;Bengtson et al, 2009). These ages are broadly consistent with the occurrence of microfossils such as Grypania (Kumar, 1995) which occur globally in strata of similar ages (Adams et al, 2017).…”

Section: Age Of the Chitrakoot Taxasupporting

confidence: 81%

Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis

Gibson

Shih

Cumming

et al. 2017

Geology

161

128

View full text Add to dashboard Cite

Shale samples were collected from outcrops that lack evidence for secondary mineralization from hydrothermal activity and weathered regions that may have experienced alteration were also avoided. Sample sets comprise several 100-200 g samples excavated 10-30 cm from the outcrop surface to target fresh material. Samples were collected along strike from a narrow stratigraphic range (<10 cm), as well as from a vertical profile (up to 5 m). The most organic-rich and least visibly-weathered samples were then chosen for digestion and isotopic

show abstract

Section: Age Of the Chitrakoot Taxasupporting

confidence: 81%

Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis

Gibson

Shih

Cumming

et al. 2017

Geology

161

128

View full text Add to dashboard Cite

show abstract

“…Slightly younger specimens of similar sizes from the Changzhougou and Changlinggou formations of China have also been interpreted as macroalgae, although some may be pseudofossils (24,25). Specimens of Grypania spiralis in the Ϸ1.6 Gya Rohtas Formation of Vindhyan Supergroup in India exhibit clear annulations and represent the oldest uncontroversial eukaryotic macrofossils (26). Thereafter, maximum size remained approximately constant for Ͼ1 billion years ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Two-phase increase in the maximum size of life over 3.5 billion years reflects biological innovation and environmental opportunity

Payne

Boyer

Brown

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

262

160

View full text Add to dashboard Cite

The maximum size of organisms has increased enormously since the initial appearance of life >3.5 billion years ago (Gya), but the pattern and timing of this size increase is poorly known. Consequently, controls underlying the size spectrum of the global biota have been difficult to evaluate. Our period-level compilation of the largest known fossil organisms demonstrates that maximum size increased by 16 orders of magnitude since life first appeared in the fossil record. The great majority of the increase is accounted for by 2 discrete steps of approximately equal magnitude: the first in the middle of the Paleoproterozoic Era (Ϸ1.9 Gya) and the second during the late Neoproterozoic and early Paleozoic eras (0.6 -0.45 Gya). Each size step required a major innovation in organismal complexity-first the eukaryotic cell and later eukaryotic multicellularity. These size steps coincide with, or slightly postdate, increases in the concentration of atmospheric oxygen, suggesting latent evolutionary potential was realized soon after environmental limitations were removed.body size ͉ Cambrian ͉ oxygen ͉ Precambrian ͉ trend D espite widespread scientific and popular fascination with the largest and smallest organisms and numerous studies of body size evolution within individual taxonomic groups (1-9), the first-order pattern of body size evolution through the history of life has not been quantified rigorously. Because size influences (and may be limited by) a broad spectrum of physiological, ecological, and evolutionary processes (10-16), detailed documentation of size trends may shed light on the constraints and innovations that have shaped life's size spectrum over evolutionary time as well as the role of the body size spectrum in structuring global ecosystems. Bonner (17) presented a figure portraying a gradual, monotonic increase in the overall maximum size of living organisms over the past 3.5 billion years. The pattern appears consistent with a simple, continuous underlying process such as diffusion (18), but could also reflect a more complex process. Bonner, for example, proposed that lineages evolve toward larger sizes to exploit unoccupied ecological niches. For decades, Bonner's has been the only attempt to quantify body size evolution over the entire history of life on Earth, but the data he presented were not tied to particular fossil specimens and were plotted without consistent controls on taxonomic scale against a nonlinear timescale. Hence, we have lacked sufficient data on the tempo and mode of maximum size change to evaluate potential first-order biotic and abiotic controls on organism size through the history of life.Here, we document the evolutionary history of body size on Earth, focusing on the upper limit to size. Use of maximum size allows us to assess constraints on the evolution of large body size and avoids the more substantial empirical difficulties in determining mean, median, or minimum size for all life or even for many individual taxa. For each era within the Archean Eon (4,000-2,500 Mya) and ...

show abstract

“…Grypania fossils are narrow ribbons, originally cylindrical, up to 13 mm long and 2 mm wide, that commonly form a regular coil up to 24 mm across (Walter et al 1990; figure 2i). Indian populations illustrated by Kumar (1995) preserve a distinct millimetre-scale annulation that may reflect underlying cell structure. These fossils are very likely of eukaryotic origin, although phylogenetic relationships are not well constrained.…”

Section: Palaeontological Estimates Of Eukaryotic Antiquitymentioning

confidence: 99%

Eukaryotic organisms in Proterozoic oceans

Knoll

Javaux

Hewitt

et al. 2006

Phil. Trans. R. Soc. B

586

409

View full text Add to dashboard Cite

The geological record of protists begins well before the Ediacaran and Cambrian diversification of animals, but the antiquity of that history, its reliability as a chronicle of evolution and the causal inferences that can be drawn from it remain subjects of debate. Well-preserved protists are known from a relatively small number of Proterozoic formations, but taphonomic considerations suggest that they capture at least broad aspects of early eukaryotic evolution. A modest diversity of problematic, possibly stem group protists occurs in ca 1800-1300 Myr old rocks. 1300-720 Myr fossils document the divergence of major eukaryotic clades, but only with the Ediacaran-Cambrian radiation of animals did diversity increase within most clades with fossilizable members. While taxonomic placement of many Proterozoic eukaryotes may be arguable, the presence of characters used for that placement is not. Focus on character evolution permits inferences about the innovations in cell biology and development that underpin the taxonomic and morphological diversification of eukaryotic organisms.

show abstract

Megafossils from the Mesoproterozoic Rohtas Formation (the Vindhyan Supergroup), Katni area, central India

Cited by 61 publications

References 11 publications

Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis

Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis

Two-phase increase in the maximum size of life over 3.5 billion years reflects biological innovation and environmental opportunity

Eukaryotic organisms in Proterozoic oceans

Contact Info

Product

Resources

About