A new species of the basal plesiadapiform <i>Purgatorius</i> (Mammalia, Primates) from the early Paleocene Ravenscrag Formation, Cypress Hills, southwest Saskatchewan, Canada: further taxonomic and dietary diversity in the earliest primates
Bibliographic record
Abstract
The fossil record of the earliest primates, purgatoriid plesiadapiforms, has become increasingly well documented during the past two decades, but their dietary preferences remain poorly understood. While the available evidence, which consists mostly of isolated teeth and incomplete jaws with teeth, suggests that purgatoriids were insectivorous to omnivorous, we describe here a new species of Purgatorius, Purgatorius pinecreeensis sp. nov., that extends the range of purgatoriid dental disparity toward greater omnivory than had been known before. Purgatorius pinecreeensis sp. nov., from the early Paleocene (Puercan) Ravenscrag Formation of southwestern Saskatchewan, differs from other species of Purgatorius in having slightly lower crowned teeth with a lower trigonid relative to talonid, blunter and more swollen major cusps, more transverse lower molar paracristids, and m3 with a more robustly developed posterior lobe. Taken together, these specializations enhanced the capacity for crushing and grinding at the expense of orthal shear, and represent the first instance of a modest degree of bunodonty in the family. The discovery of P. pinecreeensis sp. nov., along with other recently reported basal plesiadapiforms from the Puercan and Torrejonian of the northern Western Interior, lends additional support to the notion of a significant primate radiation soon after the Cretaceous–Paleogene extinction event.
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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 | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".