Excessive thickening of the cortical layer in graptolites
Bibliographic record
Abstract
SUMMARY A number of graptolites with thickened periderm, both dendroids and graptoloids, have been examined with the SEM. The thickening is by the deposition of layers of ectocortical tissue, clearly as bandages in the graptoloids. In Colonograptus colonus and some ‘diplograptids’, the thickening is most pronounced in the proximal regions of the rhabdosome, and can lead to the partial or complete occlusion of the aperture of the sicula and proximal thecae, as well as thickening the virgella. This thickening is interpreted as an adaptation connected with an extra gerontic production of cortex, which might have served as a reinforcement of the rhabdosome, or as an adaptation to modify or retain, the centre of gravity in the water column, or both. In Amphigraptus sp. the thickening appears to be common, and is concentrated on the dorsal side of the stipes. In Dendrograptus sp. thickening is also common: the main branches become excessively thickened, uniformly around the stipes, the side branches less thickened. In Cyrtograptus , thickening is rare, and appears to be gerontic, with the exception of a new form tentatively identified as Cyrtograptus in which thickening is uniform throughout the rhabdosome, and may have been formed initially. In Colonograptus and several ‘diplograptids’, the thickened proximal part shows it is much heavier than the distal part, suggesting a downwards vertical direction of the proximal end. In Amphigraptus the asymmetrical thickening suggests an orientation with the ventral side uppermost.
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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 | 0.000 |
| Science and technology studies | 0.000 | 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) | 0.003 | 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".