The Dawangou auxiliary GSSP (Xinjiang autonomous region, China) of the base of the Upper Ordovician Series: putting global chitinozoan biostratigraphy to the test
Bibliographic record
Abstract
Abstract. The Dawangou section, an auxiliary Global Stratoype Section and Point (GSSP) for the base of the Upper Ordovician Series, was sampled for chitinozoans. The 32 samples taken from the black shales of the Saergan Formation, spanning the Pterograptus elegans, Didymograptus murchisoni and Nemagraptus gracilis graptolite biozones, yielded 6536 chitinozoan vesicles. In addition to a diverse endemic assemblage, species important for international correlation were recovered, which enables the subdivision of the Saergan Formation into two chitinozoan biozones, one subzone and one provisionally recognized biozone: the Baltoscandian Laufeldochitina striata Biozone and the Laurentian Lagenochitina sp. A (sensu Achab, 1984) (/Belonechitina hirsuta) Biozone, and the Belonechitina tuberculata Subzone are recognized based on the presence of the index species, while the Baltoscandian Laufeldochitina stentor Biozone is provisionally recognized on the presence of Laufeldochitina sp. A aff. striata sensu Grahn et al., 1996 which has a range confined to the latter biozone. One new chitinozoan species is described: Cyathochitina giraffa sp. nov. and two species were assigned to a different genus: Belonechitina tuberculata comb. nov. and Hercochitina seriespinosa comb. nov.
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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 | 0.002 |
| 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".