Systematics of the Genus<i>Palaeictops</i>Matthew, 1899 (Mammalia: Leptictidae), with the Description of Two New Species from the Middle Eocene of Utah and Wyoming
Bibliographic record
Abstract
Palaeictops is a genus of Early Cenozoic Leptictidae, currently comprising six species known from Eocene faunas in the United States and Canada. Two new species, Palaeictops altimontis and P. robustus, are represented by nearly complete skulls and mandibles from the Tepee Trail (Middle Eocene) and Uinta (Middle Eocene) formations of Wyoming and Utah, respectively. They are similar to other species of Palaeictops in having a single sagittal crest, small suprameatal foramen, and an expanded cochlear fossula. Phylogenetic analysis recovered a monophyletic Palaeictops and a sister relationship of P. bicuspis and P. multicuspis with P. matthewi sister to this clade. The subfamily Leptictinae is herein recognized to comprise Blacktops, Leptictis, Megaleptictis, and Palaeictops. This group is distinctive in having a number of features that indicate a less sectorial cheektooth dentition than in the nonleptictine Prodiacodon and Myrmecoboides. The leptictines Palaeictops and Leptictis are also known from postcranial elements, and these show features, such as the distally fused tibia and fibula, that distinguish them from the condition in Prodiacodon. The Late Cretaceous genus Gypsonictops is used as an outgroup for the phylogenetic assessment of leptictids herein, but it remains uncertain whether this taxon has a close relationship with other leptictids or lies outside the crown group Placentalia.
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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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".