Middle <scp>O</scp>rdovician <i><scp>A</scp>porthophyla</i> brachiopod fauna from the roof of the <scp>W</scp>orld, southern <scp>T</scp>ibet
Bibliographic record
Abstract
Abstract A D arriwilian (late M iddle O rdovician) brachiopod fauna from the L ower F ormation of the C hiatsun G roup at J iacun, northern N yalam, southern T ibet, consists of ten brachiopod species, forming a distinct A porthophyla – P aralenorthis A ssociation. Its taxonomic composition is typical of the A porthophyla F auna that occupied lower BA 2 to upper BA 3 benthic environments on sandy lime mud substrates. The occurrence of P aralenorthis in southern T ibet is confirmed for the first time, represented by P . costata sp. nov. Numerical analyses ( PCA and CA ) of 18 D arriwilian brachiopod faunas from ten palaeoplates or terranes indicate that: (1) the A porthophyla F auna was confined to a specific latitudinal belt although it had a wide lateral distribution from the large palaeocontinents of G ondwana to L aurentia; (2) the S aucrorthis F auna, a typical late M iddle O rdovician regional fauna, is limited to a much smaller area, marginal to the G ondwana supercontinent; (3) the strong provincialism persistent in the late M iddle O rdovician contributed to increased gamma biodiversity during the G reat O rdovician B iodiversification E vent.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.008 | 0.001 |
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".