A fossil crinoid with four arms, Mississippian (Lower Carboniferous) of Clitheroe, Lancashire, UK
Bibliographic record
Abstract
One of the characteristic features used to define the echinoderms is five-fold symmetry. The monobathrid camerate crinoid genus Amphoracrinus Austin normally has five arms, but an aberrant specimen from Salthill Quarry, Clitheroe, Lancashire (Mississippian, lower Chadian), has only four. The radial plate in the B-ray supports only interbrachial and/or tegminal plates; there never has been an arm in this position. The reason why this arm failed to grow is speculative, but there is no evidence for the common drivers of aberrant growth in crinoids such as borings; rather, a genetic or developmental flaw, or infestation by an unidentified parasite, must be suspected. In the absence of the B-ray arm, the other arms of Amphoracrinus sp. have arrayed themselves at 90° to each other to make the most efficient feeding structure possible.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.010 | 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".