North American Caballines and Amerhippines of the Past 1 Million Years (Part 1)
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Horses were widely distributed in North America during the Pleistocene epoch and their fossil remains are common in sedimentary deposits of this age. Despite their rich fossil record, the systematics and taxonomy of North American Pleistocene horses remain unresolved. We evaluated a large sample of cranial and postcranial horse fossils of Irvingtonian and Rancholabrean North American Land Mammal Age. In this study, we present Part 1 of our evaluation, which centers on caballine horses, Equus (Equus). We present data (measurements and photographs) and analyses (Simpson’s ratio diagrams, scatter diagrams, and anatomical comparisons) that reveal morphological variation in North American caballine horses. These analyses serve as the basis for recognizing different morphospecies: E. (E.) scotti, E. (E.) alaskae, E. (E.) lambei (the latter two possibly representing “ecological variants” of a single species), E. (E.) niobrarensis, E. (E.) pacificus, and E. (E.) complicatus. How these morphospecies (or chronospecies or ecological variants) were phylogenetically related remains to be evaluated. Equus (E.) hatcheri may be considered as a morphological variant or chronological variant of E. (E.) niobrarensis. Equus holmesi is considered a junior synonym of E. (E.) scotti, while E. bautistensis may be regarded as a junior synonym of E. (E.) pacificus. Equus laurentius is a junior synonym of E. (E.) caballus, a synonymy proposed previously in other studies. We are uncertain about the nature of E. midlandensis. In addition, we identify morphometric and anatomical features that distinguish between Equus (Equus), North American Equus (Amerhippus), and Equus (Hesperohippus) mexicanus. This study aims to advance our understanding of the taxonomy of North American Pleistocene horses, providing a thoroughly documented catalogue as a basis for further studies.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it