Lower Aeronian (Llandovery, Silurian) graptolites of the genera<i>Rastrites</i>and<i>Stavrites</i>: systematics, biostratigraphy and palaeobiogeography
Bibliographic record
Abstract
Abstract The lower Aeronian graptolite species Rastrites longispinus longispinus Perner, R . approximatus Perner, R. peregrinus Barrande, R .? norilskensis Obut & Sobolevskaya, and Stavrites rossicus Obut & Sobolevskaya have been revised using material from China, the Czech Republic, Siberia, Canada and Spain, together with published data. Rastrites longispinus chenxui subsp. nov. is recognized as a new biogeographical subspecies known only from China and Canada. Rastrites guizhouensis Mu et al ., R. confertus Chen & Lin and Stavrites laticellatus Obut & Sobolevskaya, are all considered to be junior synonyms of S . rossicus . Rastrites geinitzii Törnquist is regarded as a junior synonym of R . longispinus longispinus ; and R . orbitus Churkin & Carter and R . hemigyratus Chen & Lin are considered to be junior synonyms of R .? norilskensis . We propose that a distinct R .? norilskensis Biozone can be recognized between a lowest Aeronian Demirastrites triangulatus or D . triangulatus – D . pectinatus Biozone in Siberia and northern Canada (possibly in South China, with future work) and the overlying Lituigraptus convolutus Biozone. Cluster analysis of the palaeogeographical distribution of species of Rastrites and Stavrites supports the hypothesis that two graptolite palaeobiographical provinces can be defined in the early Aeronian: a low‐latitude Circumequatorial Province including northern Laurentia, South China, Siberia and peri‐Siberian terranes; and a largely mid‐latitude Rheic – West Gondwana Province comprising Avalonian Britain, the Baltic area, central Europe, western and southern Europe, and cratonic North Africa. None of our studied taxa exhibits a cosmopolitan distribution. Our systematic revision has a significant impact on our palaeogeographical interpretations.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 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".