Microbially induced pseudotraces from a Pantanal soda lake, Brazil: Alternative interpretations for Ediacaran simple trails and their limits
Bibliographic record
Abstract
Abstract Despite the absence of metazoans, structures resembling animal traces are common in a soda lake from the western Brazil Pantanal wetland. Pantanal soda lakes are ecologically extreme environments that preclude complex life, allowing extremophiles to flourish. Direct observation indicates that these structures are pseudotraces, representing groove marks that result from the interaction of wave-transported floating rafts of epibenthic microbial mat fragments with the substrate. Variations in wind/wave direction and intensity result in marks of different size and morphology. The most common pseudotraces are simple and slightly curved, narrow grooves (type 1), whereas others are straight and present raised lateral ridges (type 2). Both are V-shaped in cross section. Type 3 comprises long, sinuous, shallow grooves, displaying internal crescentic laminated infill and U-shaped cross section. The similarity of these pseudotraces to Ediacaran structures usually interpreted as animal trace fossils suggests that care should be exercised in their analysis. A set of criteria is proposed to differentiate microbially induced pseudotraces from trace fossils. Analysis of Ediacaran structures needs to be performed on a case-by-case basis, taking into account morphology, orientation, and preservation style of the structure, sedimentary environment, and presence or absence of microbial mats.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".