Foraminifera from the Cambrian of Nova Scotia: The oldest multichambered foraminifera
Bibliographic record
Abstract
We report the occurrence of the oldest known multi-chambered trochospiral, planispiral and planispiral/uniserial foraminifera from the Lower to Middle Cambrian deposits in Nova Scotia (Canada). Morphologically, these forms closely resemble modern marsh foraminifera. If these are in fact similar or the same as present marsh foraminifera, their apparent lack of morphological evolution, and the agglutinated and complex multichambered nature of these foraminifera suggest that: 1) these organisms must have some unique characteristics favoring the development of a successful assemblage that appears to have survived to the present, 2) complex chamber arrangements started to develop before 500 Ma, and 3) either these forms are the ancestors to all multi-chambered foraminifera–including the calcareous foraminifera which are the dominant foraminiferal group today – or there was parallel evolution where these went undetected for 200 m.y. when the next occurrence of these chamber arrangements is reported.Similar foraminifera have been found in Carboniferous and younger deposits where it is clear these were associated with ancient marshes. These fill some of the time gap between the Cambrian forms and modern marsh species.
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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 | 0.002 | 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) | 0.001 | 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".