Early Permian conifer remains from Central Mexico and reevaluation of Paleozoic conifer morphotaxa
Bibliographic record
Abstract
This paper describes the first Permian walchian conifer from Mexico based on several specimens preserved as compressions/ impressions.The material comes from the Tuzancoa Formation in the state of Hidalgo, Central Mexico.It is described as Calnalia hidalguensis gen.nov.et sp.nov. a new conifer morphotaxon based on isolated lateral branches with leaves.This new conifer has some of the smallest branches and leaves found among previously described walchians.Calnalia hidalguensis has two types of branches (ovoid and deltoid) with simple and helically arranged leaves.Leaves are narrowly triangular to linear in front view, slightly concave and spreading (penultimate shoots) to slightly concave to slightly S-shaped (ultimate shoots), in side view.Leaves range from 3.2 mm long by 0.5 mm wide on penultimate shoots, to 1.3 -2.9 mm long by 0.4 -0.9 mm wide on ultimate shoots, with angles of leaf insertion ranging from 16º to 39º.The new species is most similar to Emporia lockardii Mapes and Rothwell, Walchia goeppertiana Florin, Walchia mucronata Florin, and Otovicia hypnoides Kerp, Poort, Swinkels & Verwer.However, none of these have the same ranges of morphological variation found in the leaves of Mexican species.The new taxon expands the diversity of walchian conifers at the end of the Paleozoic in America, and marks the beginning of new research of Permian floras in Mexico.The presence of C. hidalguensis and other gymnosperms, to be described, reinforces the presence of an arc along the Oaxaquia block that connected Mexico to the North American craton during the late Paleozoic.These new data also allow us to test hypotheses about the origin and evolution of Paleozoic floras in Euramerica.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 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) | 0.002 | 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".