New poraspids (Agnatha, Heterostraci) from the Early Devonian of the western United States
Bibliographic record
Abstract
ABSTRACT A new species of the cythaspid Poraspis is described from the Emsian (Early Devonian) Lippincott Member of the Lost Burro Formation in Death Valley, California. Poraspis thomasi, sp. nov., extends the geographic range of the genus, which had previously been reported from western Europe, Spitsbergen, the Canadian Arctic Archipelago, and District of Mackenzie. In addition, the temporal range is extended as the previously described species ranged through the Late Silurian into the Pridoli. This species includes articulated specimens showing that the oral area consisted of a single rectangular oral plate, in contrast with the view that in cyathaspids the area consisted of an arrangement of numerous finger-like plates. Also, one ventral shield shows growth lines indicating that growth of the shield occurred in a posterior direction. An additional poraspid, Lechriaspis patula, gen. et sp. nov., is described from a single specimen from the Grassy Flat Member of the Water Canyon Formation, northern Utah, that shows evidence of puncture wounds indicating predation by a eurypterid. These new heterostracans represent the first true cyathaspids to be described from the Devonian of the western United States.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| 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".