Diversification patterns in the clitambonitoid brachiopods of the Ordovician of Baltoscandia
Bibliographic record
Abstract
Two intervals of clitambonitoid diversification followed by major extinctions have been recorded in the Ordovician rocks of Baltoscandia, one during the Arenig and a second in the mid Caradoc. The Arenig radiation was characterized by high origination and extinction rates of both genera and species associated with the development of carbonate environments across the region. In addition the migration of numerous stocks of clitambonitoids out of Baltica to a number of other palaeocontinents occurred during this diversity peak during the Arenig, together with the spread of the majority of genera into a range of more local environments. A marked extinction in the Early Llanvirn coincided with shifts in sedimentation patterns whereas the diversity hike in the Mid Caradoc reflects the diversification of clitambonitoid species in both inner and outer shelf environments. The later Caradoc extinction coincided with an extensive eustatic regression event and the major restructuring of the ecosystem and brachiopod fauna. The final extinction of Baltic clitambonitoids in the late Ashgill was gradual and probably reflected an increasing dependence on more restricted niches.
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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 | 0.003 | 0.001 |
| 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) | 0.001 | 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".