Systematics and palaeobiology of the crested hadrosaurine Saurolophus from Canada and Mongolia
Bibliographic record
Abstract
Reappraisal of Saurolophus confirms Saurolophus osborni and Saurolophus angustirostris as distinct species. Synapomorphies of Saurolophus include a spike-like pseudonarial crest formed by the nasals, frontals, and prefrontals; tripartite frontals with anteroventral and posterodorsal extensions that buttress the underside of the nasals; posterodorsal process on the prefrontal that buttresses the posterolateral edge of the nasal crest; and the presence of at least one supraorbital element. Phylogenetic analysis supports the close relationship between Saurolophus, Prosaurolophus, and Kerberosaurus. Material from the Maastrichtian Moreno Formation, California, previously assigned to Saurolophus is poorly preserved and lacks important diagnostic elements. This taxon shares traits of both Saurolophus and Edmontosaurus; however, as no unambiguous synapomorphies could be identified, this material is conservatively reassigned to Hadrosaurinae indet. The integument of Saurolophus varies significantly along the length of the body in both species. For the first time in the Dinosauria, soft tissue anatomy can be used to differentiate between species of single genus. A new standardised scheme for scale descriptions is also proposed. A Saurolophus bonebed from Mongolia represents the only dinosaur bonebed that preserves skin impressions. Ontogenetic evidence from this site suggests Barsboldia sicinskii, the only other hadrosaurid from the Nemegt Formation, is a junior synonym of Saurolophus angustirostris. An Edmontosaurus bonebed from the Horseshoe Canyon Formation (Alberta) contains nine animals including at least one Albertosaurus. The assemblage was subject to exposure, trampling, and rampant scavenging over a relatively short period (<1 year?). Future directions for hadrosaurid research are discussed.
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.
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 | 0.002 | 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) | 0.001 | 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".