Cretaceous-Tertiary palynofloral perturbations and extinctions within the <i>Aquilapollenites</i> Phytogeographic Province
Bibliographic record
Abstract
A combination of detailed, intermediate and large scale stratigraphic perspectives is necessary to understand the driving mechanisms for floral change across the Cretaceous-Tertiary (KT) boundary, because short-term physical and biotic events occur within longer term trends. Most Maastrichtian palynofloral extinctions have been identified within the northern circumpolar, supra-continental, Aquilapollenites Province. In mid-continental North America, the presence of a physically defined KT boundary provides opportunities to examine contemporaneous terrestrial palynofloras over a latitudinal (also approximately paleolatitudinal) distance of 3200 km. Seventy-five percent of last appearances occur before the KT boundary at high latitudes and must have been caused by ongoing terrestrial processes. Palynofloral events directly associated with the KT boundary include both local last appearances, and inferred extinctions, and synchronous and diachronous changes in relative abundances. Two different styles of factors are reflected in these events. The first, possibly attributable to chemical or other profound atmospheric perturbations associated with the worldwide distribution of the "fireball" layer of the KT claystone, resulted in extinctions of angiosperm with a zoophilous pollination strategy. The second factor, possibly reflecting energy released during the deposition of ballistically transported impact debris or hackly (ejecta) layer of the boundary claystone, resulted in the selective, northward-attenuating removal of the canopy vegetation, best documented for southwestern Canada, which was succeeded by a fern-dominated vegetation in mid-continental North America. These consequences of the boundary event were mediated by independent, preexisting circumstances: climate (regional and through time), local depositional environment, and ongoing background extinctions and origins.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".