The completeness of the continental fossil record and its impact on patterns of diversification
Bibliographic record
Abstract
Did organisms diversify in different ways on land and in the marine realm over the Phanerozoic, or do the different diversification curves of continental and marine organisms reflect primarily methodological artifacts? To answer this question, a quantitative assessment of the completeness of the global continental fossil record is indispensable. We used comparisons between continental and marine fossil diversity and between past and present-day patterns of continental diversity to assess the absolute and relative completeness of the continental fossil record. Collector's curves of the number of described families over the past 200 years suggest that the global continental fossil record, and even that of European and North American tetrapods, is still highly incomplete. Nevertheless, relative proportions of major continental and marine taxa, patterns of tetrapod endemism, and familial durations suggest that the family-level continental fossil record is reasonably representative. We found that, although continental fossil richness is correlated with the amount of terrestrial clastic sediment available for sampling, the exponential diversification curve of continental metazoans is unlikely to be an artifact of this rock bias. Diversification of the continental fauna appears to have been essentially exponential since the Devonian, with little evidence of major extinction events.
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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 | 0.009 | 0.033 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| 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".