Early Devonian putative gyracanthid acanthodians from eastern CanadaInternational Geoscience Programme (IGCP) Contribution 491, Middle Palaeozoic Vertebrate Biogeography, Palaeogeography, and Climate.
Bibliographic record
Abstract
In 1890, Traquair assigned isolated fin spines from the Early Devonian of eastern Canada to a new gyracanthid acanthodian Gyracanthus incurvus , based on the similarity of the distinctive oblique ridges on the spines to the ornament on the large robust fin spines of Gyracanthus spp. from the British Carboniferous Coal Measures. Other similarly ornamented spines from the Early Devonian of Germany were tentatively assigned in 1933 by Gross to the same genus as a new species Gyracanthus? convexus . Based on examination of the type material, as well as newly collected specimens from Emsian sandstones and mudstones of the Gaspé Peninsula, Quebec and the Atholville beds, New Brunswick, we erect a new genus Ankylacanthus gen. nov. for these two species. Spines of the new genus are distinguished by being laterally flattened and thin-walled, with a single row of denticles along one side of the posterior groove, and having thin spine ridges ornamented with low smooth nodes. Other Early to Middle Devonian specimens in South America, Saudi Arabia, and Iran are also tentatively referred to the new genus, which seems to have had an early (Lochkovian–Pragian) cross-north Gondwanan distribution, transferring into Laurentia and spanning Emsian–Eifelian times.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".