Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution
Bibliographic record
Abstract
Cryolophosaurus elliotiHammer and Hickerson, 1994, from the Early Jurassic Hanson Formation of the Central Transantarctic Mountains, represents a theropod dinosaur from a period of time and geographical area that are poorly sampled with respect to dinosaur taxa. An in-depth morphological description of Cryolophosaurus is presented here, along with a rigorous phylogenetic analysis of theropod relationships consisting of 347 characters and 56 taxa, in an attempt to clarify the relationships of Cryolophosaurus and to provide insight into questions surrounding early theropod evolution. Cryolophosaurus is characterized by a unique cranial crest, formed primarily by the lacrimals, a pronounced constriction of the squamosal and jugal bones across the infratemporal fenestra, and extremely elongate cranial processes on the cervical ribs. Several shared characters, including the presence of a slot-shaped foramen at the base of the nasal process of the premaxilla, nasolacrimal crests and erect tab-like dorsal processes on the articular, suggest affinities between Cryolophosaurus and a clade of medium-bodied Early Jurassic theropods that includes ‘Dilophosaurus’sinensis, Dracovenator regenti and Dilophosaurus wetherilli. This clade is recovered as sister-taxon to a Neoceratosauria + Tetanurae clade, rendering both a traditional Coelophysisoidea and Ceratosauriaia non-monophyletic. Cryolophosaurus represents the largest known Early Jurassic theropod, and marks the beginning of theropod occupation of the dominant predator niche in the Mesozoic.
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 | 0.001 |
| 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 | 0.000 |
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".