Early Eocene Paromomyidae (Mammalia, Primates) from the southern Bighorn Basin, Wyoming: Systematics and evolution
Bibliographic record
Abstract
We present a critical review of the alpha taxonomy and evolution of Eocene North American paromomyid primates, based on analysis of more than 570 stratigraphically controlled dental and gnathic specimens from the early Eocene of the southern Bighorn Basin, Wyoming (Wasatchian, Willwood Formation). In addition to documenting numerous previously unpublished specimens of known taxa (including deciduous teeth), we also describe a new species, Phenacolemur willwoodensis n. sp., from the upper part of the Willwood Formation (Wa 5 and 6). The new species is intermediate in size between Phenacolemur simonsi and Phenacolemur citatus and has both primitive features (e.g., retention of m2–3 paraconids, relatively long molar trigonids) and derived traits (e.g., relatively reduced paraconid on m1 and no p4 paracristid, unlike Paromomys ). Overall patterns of dental evolution in southern Bighorn Basin paromomyids provide some support for previously hypothesized periods of faunal change (Biohorizons). In particular, Phenacolemur praecox evolves into the similarly sized but morphologically distinct Phenacolemur fortior at Biohorizon A, and P. fortior is replaced by P. citatus just below Biohorizon B. Two taxa previously believed to have become extinct at Biohorizon A (Ignacius graybullianus, P. simonsi) are shown to have persisted about a million years longer than previously thought. The Bighorn Basin paromomyids are of general interest in comprising a very dense sample that allows for the study of patterns of evolution against the backdrop of well-understood patterns of change in other mammalian lineages, and in climatic variables.
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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 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".