The Svanbergfjellet Formation: eukaryotic life in a Tonian Sea
Bibliographic record
Abstract
Exceptionally preserved organic-walled microfossils of the Svanbergfjellet Formation, Svalbard document the diversity of eukaryotes in a Tonian (1000–720 myr ago) shallow sea. We review this fossil Lagerstätte and re-sample it at the highest stratigraphic resolution to date. We place the Lagerstätte in an updated age model and evaluate fossil taphonomy. The Svanbergfjellet Formation is one of the most biodiverse units in the Tonian, c . 50% more diverse than the average fossiliferous Tonian unit. It notably preserves the green alga Proterocladus and the possible green alga Palaeastrum . These multicellular fossils, when combined with others elsewhere, suggest that green algae were well established in Tonian marine ecosystems, but substantially predate organic biomarkers that record a dominant green algal contribution to marine primary productivity only by the Ediacaran. Svanbergfjellet also includes several problematic taxa with complex multicellular morphologies (e.g. Jacutinema and Valkyria ) that require further investigation into their phylogenetic placement, but that could substantially add to the known diversity of crown eukaryotes in the Proterozoic.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".