THE FIRST UNEQUIVOCAL NORTH AMERICAN OCCURRENCE OF THE MOSASAUR HAINOSAURUS (REPTILIA) FROM THE CRETACEOUS PIERRE SHALE OF THE MISSOURI RIVER TRENCH, SOUTHERN SOUTH DAKOTA
Bibliographic record
Abstract
One of the largest reptiles to occur in the seas during the end of the Cretaceous was the mosasaur, Hainosaurus. The mosasaur attained lengths of over 10 meters with a meter-long skull and is a tylosaurine mosasaur, a top predator. Hainosaurus bernardi was originally described in 1885 from Maastrichtian deposits in Belgium based upon a partial skeleton and a second skull. Other reports of Hainosaurus from the Old World have occurred, but its occurrence in North America has been questioned. The first report of the genus in North America, Hainosaurus pembinensis was from the early Campanian Pembina Member of the Pierre Shale in Canada. Later workers have doubted the assignment of the Canadian taxon to Hainosaurus, and many authors have considered the taxon as a species of the closely allied genus, Tylosaurus. A number of characters have been utilized to define Hainosaurus, but many have been found in other taxa. Perhaps the most definitive character of Hainosaurus is that the pineal opening is shared by the frontal and parietal bones, rather than being confined to the parietal. Until now, no other North American mosasaur, including the Canadian taxon, exhibits a clearly shared pineal opening. Now, a new specimen found by Mr. Paul Neumiller from the late Campanian DeGrey Member of the Pierre Shale along the shore of the Missouri River in Gregory County exhibits the shared pineal opening. In addition, other characters suggested as characteristic of Hainosaurus including relatively smooth surfaces on the teeth, interlocking premaxillary-maxillary suture, and a prominent internal process of the suprastapedial process of the quadrate occur on the newly discovered specimen. Other apomorphies suggest that the specimen represents a new species. Evidently, tylosaurine specimens from the early Campanian exhibit the initial divergence of Hainosaurus from Tylosaurus, and by the late Campanian and Maastrichtian, the transition had been completed.
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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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".