Regional, Depositional, and Chronologic Comparisons of Pleistocene Turtle Richness in North America
Bibliographic record
Abstract
Records of turtle remains from Pleistocene deposits in western North America are scarce, suggesting that turtles were uncommon in western landscapes throughout the Pleistocene. However, low numbers of fossils do not necessarily correlate with rarity in the past because taphonomic bias can have a marked impact on shaping what is preserved in the fossil record. We compiled minimum species richness data for 8 geographic regions by depositional setting (caves and open-air sites) and used a 2-factor analysis of variance to examine the effects of geographic region and depositional setting on turtle species richness. We did not find a statistically significant effect of depositional setting on turtle richness, suggesting that the paucity of turtles in the Pleistocene of western North America does not result from that particular form of taphonomic bias. Also, we found a strong regional variation in turtle richness that was dependent on time interval, suggesting a potential shift in regional patterns of richness since the Pleistocene.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 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".