New Occurrences of Fossil Macrocheira (Brachyura, Inachidae) from the North Eastern Pacific
Bibliographic record
Abstract
New specimens of the fossil Macrocheira collected from Eocene to Miocene rocks of Canada and western United States increase the fossil record of the Inachidae (MacLeay, 1838). Macrocheira is represented by only one extant species, M. kaempferi, endemic to Japan and Taiwan. Two fossil species have previously been described from Washington State: M. longirostra (Schweitzer and Feldmann, 1999), from the Eocene Quimper Sandstone, and M. teglandi (Rathbun, 1926), from the Oligocene Makah Formation. Three new species are reported: M. jayi n. sp. from the late Eocene to Oligocene Hesquiat Formation of Vancouver Island, British Columbia, Canada; M. sullivani n. sp. from the late Eocene to early Oligocene Keasey Formation of Oregon State, U.S.A.; and M columbiaensis n. sp. from the early to middle Miocene Astoria Formation of Washington State, U.S.A. Several Macrocheira species have also been reported from the Miocene of Japan; however, their systematic position is tenuous and therefore they are referred to as Macrocheira sp. aff. M. kaempferi. With the description of three new species of Macrocheira, the number of fossil species is increased to five and the genus is now well established in the North Eastern Pacific from the Eocene to Miocene.
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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 | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| 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".