Crayfish-like arthropod trackways from the fluvial Wapiti Formation (Upper Cretaceous), Alberta, Canada
Bibliographic record
Abstract
Abstract This study documents and analyzes arthropod trackways from the Upper Cretaceous Wapiti Formation, located in west-central Alberta, Canada. In general, the ichnotaxonomy of arthropod trackways is problematic due to inconsistent use of diagnostic criteria in previous studies. Thus, the trackways from the Wapiti Formation are described following recently defined criteria to facilitate future ichnotaxonomic reevaluations. Judging primarily from the number and morphology of the imprints and the symmetry of the track series, the trackways are identified as Octopodichnus cf. O. raymondi Sadler, 1993. Other relevant track attributes include heteropody and great imprint depth. The mudstone slabs bearing the trackways also contain other well-preserved invertebrate trace fossils along with abundant silicified plant material. The silicified plant fragments, taken together with bentonite overlying the trace-bearing surface, suggest volcanic ash played a role in preserving the trackways. The associated traces include burrows, fecal mounds, and surficial marks and contribute to a diverse invertebrate trace-fossil assemblage. The Wapiti Formation trackways are attributed to crayfish or similar decapods and were emplaced in a succession interpreted to have been deposited in a swampy floodplain environment. By contrast, previously described examples of Octopodichnus have typically been attributed to arachnids in aeolian/desert environments. This paper expands the ichnological record of crayfish-like arthropods from the Late Cretaceous and contributes to the underexplored invertebrate fossil record of the Wapiti Formation and, more broadly, Cretaceous strata in the Western Canada Sedimentary Basin.
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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 | 0.004 | 0.005 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| 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".