The phylogenetic affinity of the Ordovician trilobites <i>Agerina</i>, <i>Forteyaspis</i> gen. nov., and related genera, with new and revised species from Canada and the United States
Bibliographic record
Abstract
A phylogenetically related group of variably well-known Ordovician trilobites have in the past been assigned to six separate genera and a number of families, and their taxonomic cohesiveness has not always been recognized. When most of them have been understood to form an evolutionarily related group, they have historically most often been assigned to the genus Agerina Tjernvik, 1956, and assigned initially to Bathyuridae Walcott, 1886, and more recently to Leiostegiidae Bradley, 1925. The systematics of this group is revised, and its 25 formally named species are assigned to four potentially monophyletic genera. Ontogenetic information from a new silicified species, together with some adult morphology, demonstrates that the group is unambiguously related to the Ordovician family Phillipsinellidae Whittington, 1950, to which it is assigned as a suite of less derived genera. The new genus Forteyaspis (type species Forteyaspis idoli sp. nov. from the Darriwilian of western Newfoundland, Canada) is proposed for four Laurentian species, and other species are assigned to the genera Agerina, Brackebuschia Harrington and Leanza, 1957, and Hexianella Zhang in Qiu et al. Other new species are Agerina boygeorgei (Floian, Nevada, USA) and Forteyaspis adamanti (Floian, western Newfoundland, Canada). Forteyaspis norrisi (Ludvigsen, 1980) is photographically revised.
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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 | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 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".