The planktonic foraminifera of the Jurassic. Part I: material and taxonomy
Bibliographic record
Abstract
The taxonomy is modernized and updated for Jurassic planktonic foraminifera using all available literature and stratigraphic series of sediment samples from Canada, Portugal, France, Switzerland, Poland, Lithuania, Russia and Dagestan. The regional stratigraphy of all sampled sections is outlined. Many of the 65–200 µm sample residues yielded well-preserved free specimens, with local assemblages containing up to six species. Thin sections were studied also but do not allow detailed taxonomy. Two genera are described: Globuligerina and Conoglobigerina. Globuligerina probably appeared in the late Toarcian (late Early Jurassic) and Conoglobigerina first occurred in middle Oxfordian (early Late Jurassic). A principal difference between Globuligerina and Conoglobigerina is that the former has a smooth to pustulose wall surface texture and the latter a reticulate wall surface texture. Within the two genera, ten species are described, including from older to younger: Globuligerina dagestanica (Morozova), G. avariformis (Kasimova), G. balakhmatovae (Morozova), G. oxfordiana (Grigelis), G. bathoniana (Pazdrowa), G. jurassica (Hofman), G. oxfordiana (Grigelis) calloviensis Kuznetsova emended, G. tojeiraensis Gradstein, Conoglobigerina helvetojurassica (Haeusler), C. grigelisi Gradstein and C. gulekhensis (Gorbachik and Poroshina). The coarsely perforate 'Globuligerina' stellapolaris needs more investigation to establish its identity as a Jurassic or a Late Cenozoic taxon (Gradstein 2017a). Globuligerina balakhmatovae, G. oxfordiana and G. bathoniana occur from Bajocian through early Kimmeridgian, or even Tithonian. Subtle morphological trends may refine stratigraphic usage. Other taxa have shorter stratigraphic ranges. Nineteen plates and ten type species figures detail morphology of all taxa. For key taxa, both the types and specimens from other localities are illustrated.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".