A New Ammonoid Zone of the Upper Carnian Substage in Northeastern Russia
Bibliographic record
Abstract
Abstract A review of the biostratigraphic division of the Upper Carnian substage of the Boreal paleobiogeographic Realm by ammonoids is presented. The history of identifying the yakutensis ammonoid zone of the Upper Carnian in Northeastern Russia and the evolution of the views on its volume and paleontological characteristics are considered. The systematic composition and stratigraphic distribution of ammonoids within the yakutensis zone in the sections of Northern Priokhot’e (Sea of Okhotsk region), the Adycha River basin and the right bank of the lower reaches of the Lena River are revised. It is established that the species “Sirenites” (=Orientosirenites) yakutensis Kiparisova is confined to the lower part of the yakutensis zone (in its previous volume), whereas Orientosirenites bytschkovi Konstantinov is bound to its upper part. In this regard, the position of the upper boundary of the yakutensis zone is changed, and it is proposed that a new bytschkovi zone overlapping the yakutensis zone (in the new volume) should be identified. The yakutensis and bytschkovi zones are widespread and are traced in the stratigraphic sequence in a series of the sections on the territory of Northeastern Russia. In the presence of the common genus Orientosirenites, they are correlated with the Jovites borealis beds of Arctic Canada and their equivalents: the upper subzone of the Tropites welleri zone in British Columbia and the upper part of the Tropites subbullatus zone in the Alps.
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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 | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".