A new Early Devonian (Emsian) arthrodire from the Northwest Territories, Canada, and its significance for paleogeographic reconstruction
Bibliographic record
Abstract
An heterostiid arthrodire, Herasmius dayi sp. nov., is described from upper Lower Devonian marine deposits of the Bear Rock Formation along the Anderson River, Northwest Territories, Canada. New elements described for the genus for the first time include the suborbital, submarginal (also new for the family Heterostiidae), the lateral shoulder girdle with posterior lateral, anterior dorso-lateral, and posterior dorso-lateral plates and possible infragnathal plate. We present a new reconstruction of the cranial region of Herasmius, previously known only from supposedly freshwater – shallow marine deposits of roughly the same age in the Wood Bay Group of Spitsbergen. The late Early Devonian fishes that are common to the Arctic region of northwestern Canada and the island of Spitsbergen in the Svalbard archipelago of Norway, the porolepiform Heimenia and the arthrodire Herasmius described here, demonstrate the existence of a barrier-free paleogeographic connection between those continental blocks by the late Early Devonian. Comparison of the entire Anderson River vertebrate fauna with other boreal faunas of similar age indicates additional paleogeographic connections north of and around the Old Red Sandstone Continent to the Baltic region, central Europe, and even to the New Siberian Islands and South China, in contrast to most current published paleogeographical reconstructions.
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 | 0.003 | 0.003 |
| Science and technology studies | 0.003 | 0.002 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".