Gastéropodes à la carte: durophagy on Ordovician gastropods from Manitoulin Island, Canada
Bibliographic record
Abstract
Shell repairs resulting from presumed failed predation were found in gastropods from the Late Ordovician (Cincinnatian; Richmondian) mid to upper Kagawong Submember, Georgian BayFormation, on Manitoulin Island, Ontario, Canada. The bryozoan-mollusc biota and lithology of this unit suggest nearshore, shallow (<10 m), low energy (lagoonal) conditions which byanalogy with relatively recent faunas and carbonates of similar character may point to a mesotrophic to eutrophic nutrient regime. Division of the number of individual shells with atleast one scar by the total number of shells in each sample, yielded a shell repair frequency of 4.8% for 207 (total) specimens of Lophospira trilineata and 35.7% in 28 specimens (total) ofTrochonemella sp. Repairs in Trochonemella occur primarily in the largest size class, suggesting that a size refuge was achieved by this species. The low repair frequencies observed in L. trilineata suggest that this species experienced a higher predation success rate or a lower level of predation pressure. This is the only case study to date which documents Ordovician shell repair frequencies in consistent, homogenous sample sets collected from the same stratigraphic unit, evaluated against standardized analytical approaches. The results suggest that the paradigm of a standardized low level of shell repair in Ordovician and Silurian gastropods is oversimplistic, and that a range of frequency rates can be expected.
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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 | 0.003 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".