Diversity and variation of theropod dinosaur teeth from the uppermost Santonian Milk River Formation (Upper Cretaceous), Alberta: a quantitative method supporting identification of the oldest dinosaur tooth assemblage in Canada
Bibliographic record
Abstract
The Santonian Deadhorse Coulee Member of the Milk River Formation preserves the oldest dinosaur body fossils found in Alberta. However, vertebrate remains consist almost exclusively of isolated elements and microvertebrate assemblages. Here, 1572 relatively complete shed non-avian theropod teeth from 20 localities in the Deadhorse Coulee Member are measured and analyzed to assess species diversity. Teeth are referred to or similar to Tyrannosaurinae indet., cf. Richardoestesia gilmorei , cf. Richardoestesia isosceles , Dromaeosauridae indet., Dromaeosaurinae indet., Velociraptorinae indet., and cf. Paronychodon lacustris . For the taxa identified, the large sample size allows for the assessment of their range of variation and accurate identification, without the benefit of comparable material of this age. Multivariate statistics, including a principal component analysis and a canonical variate analysis, provide reasonable separation of all taxa, although better results are achieved by separate analyses based on qualitative observations of denticle shape. The best results of the canonical variate analysis identified 96.0% of specimens correctly. This corroborates the qualitative identification of specimens and illustrates a valid way of evaluating diversity in areas and formations from which no described jaw material is known.
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How this classification was reachedexpand
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 | 0.001 | 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 | 0.001 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".