Revision of the aïstopod genus<i>Phlegethontia</i>(Tetrapoda: Lepospondyli)
Bibliographic record
Abstract
The aïstopod family Phlegethontiidae is restudied based on new specimens from Pit 11 of Mazon Creek, Illinois, and the coal shales of Nýřany, Czech Republic, as well as most available specimens from North America. Phlegethontiids have highly fenestrate skulls, with orbits placed just anterior their skull's mid point. Dermal skull bones are greatly reduced in number and limited in extent, whereas the endochondral braincase is hyperossified. The frontals are fused medially and enclose the parietal foramen and anterior sagittal crest. As in most other aïstopods, the quadrate, pterygoid, and epipterygoid are fused into a composite bone, the palatoquadrate complex. Details of cranial anatomy contradict a previous model of cranial kinesis by severely limiting the skull's potential mobility. Remnants of the pectoral girdle are present, perhaps due to the presence of an operculum–opercularis-like connection to the stapes. No remnants of the pelvis are present. Three species are recognised within the family.Phlegethontia linearishas short anterior vertebrae, high neural spines on at least the anterior four vertebrae, and vertebrae number between 230–250 in total.Phlegethontia longissimahas low neural spines throughout the column, anterior vertebrae that are twice as long asP. linearis, and only 200–210 total vertebrae.Sillerpeton permianum, known from a single braincase and an unassociated string of vertebrae, is distinguished fromPhlegethontiaby the retention of a separate foramen for the passage of the occulomotor nerve.Phlegethontia“phanerhalpa” is a tiny braincase fragment that differs from the other species ofPhlegethontiaonly in the placement of the jugular foramen relative to the centre of the foramen magnum. This is probably a size-related feature, andP.“phanerhalpa” is considered a nomen dubium.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.003 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.002 |
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".