A new species of <i>Pityostrobus</i> (Pinaceae) from the Cretaceous of California: moving towards understanding the Cretaceous radiation of Pinaceae
Bibliographic record
Abstract
The evolutionary history of Pinaceae is documented by numerous fossils, which include a number of anatomically preserved ovulate cones with many systematically informative characters. To date, four extinct genera have been recognized: Pseudoaraucaria, Pityostrobus, Obirastrobus and Eathiestrobus. A new pinaceous cone from the Early Cretaceous of California is described as Pityostrobus pluriresinosa sp. nov., adding to the diversity of known Cretaceous pinaceous cones. Phylogenetic analysis places the new fossil cone in the pinoid clade along with Pinus, Eathiestrobus and numerous species of Pityostrobus. Combined with a non-metric multidimensional scaling ordination, the data reinforce that while Pityostrobus does not represent a natural genus, it likely reflects the rapid evolution of Pinaceae by showing that ovulate cone morphospace was widely occupied by Pityostrobus that has become more restricted in extant genera. Early Cretaceous taxa from Europe and eastern North America show the broadest occupation of morphospace, which then became more restricted to morphologies typical of the pinoid clade in the Late Cretaceous. Taxa from western North America and Asia are more similar to extant genera and occupy a smaller part of the morphospace, highlighting that eastern North America–Europe probably represents an original centre of early diversification for Pinaceae.
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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 | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".