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 speciesRastrites longispinus longispinusPerner,R. approximatusPerner,R. peregrinusBarrande,R.? norilskensisObut & Sobolevskaya, andStavrites rossicusObut & Sobolevskaya have been revised using material from China, the Czech Republic, Siberia, Canada and Spain, together with published data.Rastrites longispinus chenxuisubsp. nov. is recognized as a new biogeographical subspecies known only from China and Canada.Rastrites guizhouensisMuet al.,R. confertusChen & Lin andStavrites laticellatusObut & Sobolevskaya, are all considered to be junior synonyms ofS. rossicus.Rastrites geinitziiTörnquist is regarded as a junior synonym ofR. longispinus longispinus; andR. orbitusChurkin & Carter andR. hemigyratusChen & Lin are considered to be junior synonyms ofR.? norilskensis. We propose that a distinctR.? norilskensisBiozone can be recognized between a lowest AeronianDemirastrites triangulatusorD. triangulatus – D. pectinatusBiozone in Siberia and northern Canada (possibly in South China, with future work) and the overlyingLituigraptus convolutusBiozone. Cluster analysis of the palaeogeographical distribution of species ofRastritesandStavritessupports 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 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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".