A new species of tylosaurine mosasaur from the upper Campanian Bearpaw Formation of Saskatchewan, Canada
Bibliographic record
Abstract
Mosasaurs assigned to the genus Tylosaurus have been reported from the North Atlantic Circle Basin, including the Western Interior Seaway in North America and Europe, from the Turonian of Chihuahua, Mexico, to the early Maastrichtian of Belgium. The youngest record of Tylosaurus in North America is from the middle Campanian of the Pierre Shale, South Dakota. Data obtained by examination of an almost complete skull and associated postcranial elements of a large tylosaurine mosasaur from the upper Campanian of Saskatchewan supports the recognition of this specimen as a new species, Tylosaurus saskatchewanensis sp. nov. The specimen, collected from the Bearpaw Formation, southern Saskatchewan, Canada, presents unique features and combinations of features. It is recognized as a tylosaurine based on: edentulous rostrum; relatively long suprastapedial process of quadrate not reaching infrastapedial process; predental anterior extension of dentaries; and 12–13 maxillary and dentary teeth. Some of the characters that support recognition of the new species include: exclusion of prefrontal from dorsal rim of orbit by anterior process of postorbitofrontal; frontal extends anteriorly well into narial openings; well developed dorsal midline eminence of frontal; straight margins of parietal table; small infrastapedial process of quadrate located high on quadrate shaft almost touching suprastapedial process; thick tympanic ala of quadrate; 55 vertebrae anterior to chevron-bearing caudals; and rounded astragalus with big semicircular crural emargination. The new species represents the most northern occurrence of the genus and the subfamily and extends the stratigraphical distribution of the genus Tylosaurus in North America, occupying the northern Western Interior Seaway during the late Campanian. http://zoobank.org/urn:lsid:zoobank.org:pub:55338D44-B3C7-4F9C-8B51-C29DB9B99364
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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 | 0.004 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".