3D chemometric model and frond architecture of Alethopteris ambigua (Medullosales): Implications for reconstruction and taxonomy
Bibliographic record
Abstract
The postulated relationship between chemistry and frond architecture is further tested based on a 450 mm frond segment \nAlethopteris ambigua Lesquereux pars from the Sydney Coalfield (Canada), this being the largest specimen known for this species. \nMicromorphology demonstrated amphistomatic rachides with larger anomocytic stomata than on the hypostomatic pinnules, \nand rachial epidermal cells that are irregularly elongate to polygonal-rectangular, intermingled with more rectangular isodiametric \ncells, with hardly any change over the segment. Functional groups or chemical structural groups, however, are continuously variable \nover the frond segment, allowing meaningful comparisons between frond parts. Based on these data, a three-dimensional “model” \nis derived which explains the relationship between the frond architecture and changes in chemical structural groups. Furthermore, \nthe aromatic-rich compounds correlate with robust and stiffer proximal frond parts, whereas the aliphatic-rich compounds correlate \nwith the slender and flexible distal parts. The former reflects lignin-related compounds in the basal part of the frond, and the latter \ntannin and resin-like chemicals as secondary metabolites in pinnules and midveins as the defense against herbivory. Strengthening the \nrelationship between the hypothesized fossil chemistry-frond architecture is the testable prediction of chemistry of the “missing parts” \nin the likely quadripinnate A. ambigua frond, i.e. the petiole, frond bifurcation, and their adjacent proximal and most robust parts.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".