New stratigraphic records (Albian-Campanian) of Rhinobatos sp. (Chondrichthyes; Rajiformes) from the Cretaceous of Kansas
Bibliographic record
Abstract
Guitarfish (Rhinobatidae) are a conservative group of extant rays with worldwide distribution and a fossil record that extends as far back as the Jurassic (Toarcian). Modern representatives of the family inhabit shallow tropical and sub-tropical waters, at depths less than 200 m, as well as some fresh water environments. Although complete specimens are known, the most abundant fossil remains are small, isolated teeth (less than 2 mm, measured mesiodistally). In North America, the earliest record of Rhinobatos sp. is from Lower Cretaceous (Lower Albian) of Texas. Rhinobatos sp. has been reported from Cretaceous rocks in other areas of the U.S. Western Interior including the Albian-Campanian of Texas, the Turonian and Santonian of Kansas, Cenomanian of Nebraska, Cenomanian and Turonian of New Mexico and South Dakota, and Coniacian of Saskatchewan, Canada. Recent discoveries of Rhinobatos incertus teeth from the Upper Albian to the Lower Campanian in the Cretaceous of Kansas document a reasonably continuous presence of the species in a variety of marine environments within the Western Interior Sea. New Kansas records of R. incertus teeth are from: McPherson County, Kiowa Shale (Upper Albian); Russell County, Dakota - Graneros Shale contact (Middle Cenomanian); Jewell County, Codell Sandstone (Middle Turonian), and; Trego County, Smoky Hill Chalk (Upper Coniacian) and Logan County, Smoky Hill Chalk (Lower Campanian).
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".