Asterolepis alticristata n. sp. (Antiarchi) from the Upper Devonian (Frasnian) of Nunavut, Canada, and a report on the antiarch diversity of the Fram Formation
Bibliographic record
Abstract
A large collection of fossils from the NV2K17 locality, Upper Devonian (Frasnian) Fram Formation, Ellesmere Island, Nunavut, Canada, represents at least two species of Asterolepis. The first, Asterolepis alticristata n. sp., is diagnosed by a tall midline crest that rises sharply from the tergal angle of the anterior median dorsal plate, reaches maximum height at around the position of the lateral corners, and then drops to form a low midline crest along the posterior median dorsal plate. The second species is identified as Asterolepis cf. radiata according to an ornament of radiating rows of conjoined tubercles and ridges on the available thoracic plates (anterior median dorsal, posterior median dorsal, and mixilateral). We describe additional antiarch material from the NV2K17 locality, including an anterior median dorsal plate of Bothriolepis sp. indet., and from localities throughout the Fram Formation. The antiarch occurrences in the Fram Formation conform to a possible faunal turnover from one dominated by asterolepidoids low in the formation to one dominated by bothriolepidids high in the Fram Formation. At the NV2K17 locality, in the middle of the Fram Formation, members of the two groups appear together.
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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 | 0.004 | 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) | 0.002 | 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".