EARLY FRESHWATER DIATOMS FROM THE UPPER CRETACEOUS BATTLE FORMATION IN WESTERN CANADA
Bibliographic record
Abstract
Abstract Despite the rise of marine diatoms in the world's oceans throughout the Cretaceous, only a handful of fossil localities worldwide detail invasion of freshwater habitats by diatoms commencing in the Late Cretaceous. We report on the occurrence of numerous freshwater diatom specimens and species from the Battle Formation, an extensive freshwater locality in western Canada that formed in the Late Cretaceous approximately 66.5 million years ago (Ma). The formation represents one of the oldest known localities worldwide harboring definitive remains of freshwater diatoms, contains the oldest known freshwater specimens of the centric diatom genus Aulacoseira, and confirms that these early Aulacoseira colonizers formed filaments linked together with interdigitating spines. We further document a high diversity of araphid pennate diatoms belonging to the order Fragilariales. Seven pennate morphotypes were uncovered, six of which definitively lacked a raphe and whose closest modern relatives are in the genera Fragilariforma, Fragilaria, and Stauroforma. Given the extensive coverage of the Battle Formation, it is possible that it represents a network of numerous smaller shallow waterbodies that collectively offered a diversity of environments for colonization, making it a unique deposit for examination of early freshwater diatoms.
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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 | 0.003 | 0.004 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".