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Record W4414795546 · doi:10.18261/let.58.4.6

Allometric growth and intraspecific variation of the craniomandibular bones of <i>Tarbosaurus bataar</i> (Theropoda, Tyrannosauridae): a geometric morphometric approach

2025· article· en· W4414795546 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueLethaia · 2025
Typearticle
Languageen
FieldMathematics
TopicMorphological variations and asymmetry
Canadian institutionsUniversity of Alberta
FundersFundação de Amparo à Pesquisa do Estado de São PauloNatural Sciences and Engineering Research Council of CanadaDinosaur Research InstituteLondon South Bank University
KeywordsAllometrySkullIntraspecific competitionCrestMandible (arthropod mouthpart)CraniofacialVariation (astronomy)Arthropod mouthparts

Abstract

fetched live from OpenAlex

Since it was first described in 1955, many fossils of the tyrannosaurid theropod Tarbosaurus bataar have been recovered from the Upper Cretaceous Nemegt Formation of Mongolia and its contemporaneous units in east Asia. Among these, there were individuals of different sizes and stages of maturity, but not much research has been done on the changes that occurred during the growth of this dinosaur. In this work, growth trajectories in the shape of various, individual craniomandibular bones of Tarbosaurus bataar are examined through geometric morphometrics. Several major changes in craniofacial anatomy are observed through the growth series, including increases of the relative heights of the dentary, jugal, maxilla, and nasal; the transition of the lacrimal from a T-shape to a 7-shape; negative allometric growth in the anteroposterior length of the orbit; increased sizes of the cornual processes of the postorbital and the ventral flange of the jugal; broadening of the frontal accompanied by an enlargement of the dorsotemporal fossa; and widening and thickening of the nuchal crest so that the midlength of the parietal appears relatively narrower. Such results indicate the main allometric shape change patterns in craniomandibular anatomy of Tarbosaurus bataar were broadly congruent with those of other tyrannosaurids, particularly with Tyrannosaurus rex. It is assumed that many of these changes were related to disproportionate increase of the bite forces and strengthening the skull structure during growth. Additionally, a significant amount of variation appears to be uncorrelated with size, suggesting that Tarbosaurus bataar, like other theropod dinosaurs, had significant intraspecific variation in craniomandibular anatomy.

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Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.002
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.824
Threshold uncertainty score0.637

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0020.012
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.018
GPT teacher head0.244
Teacher spread0.227 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it