THE BARK OF THE LATE TRIASSIC ARAUCARIOXYLON ARIZONICUM TREE FROM PETRIFIED FOREST NATIONAL PARK, ARIZONA
Bibliographic record
Abstract
This paper contains a description of the only known non-banded bark in the geologic record. The bark is attached to a branch of the Araucarioxylon arizonicum tree that was found recently in the Late Triassic Chinle Formation (~ 220 Mya) in Arizona. In the fossil the vascular cylinder is almost totally enclosed in rough bark 2–11 mm in thickness. The inner bark is less than 1 mm thick and comprises a very narrow zone of presumed phloem containing infrequent fibers. The outer bark varies in thickness up to 10 mm, and consists of curving lenses of sequent periderm free of both dilation tissue and resin canals but is quite unlike the banded bark of Araucaria heterophylla. Wide zones of very thin-walled rectangular parenchyma cells arranged in radial files and groups of thin-walled spongy parenchyma, and small clusters as well as solitary sclerenchyma occur in the rhytidome. The vascular cambium contains 1–4 fusiform cells per radial file. Uniseriate rays are common in the secondary xylem and extend to the cambial zone. Small (1 mm in diameter), simple tunnels in the bark and wood indicate that the branch was attacked by phytophagous insects. A possible petrified beetle larva similar in form and size to Anobium is associated with these tunnels.
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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 | 0.000 |
| 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".