Phylogeny and Adaptive Radiation of the Neograptina (Graptoloida) During the Hirnantian Mass Extinction and Silurian Recovery
Bibliographic record
Abstract
SUMMARY Cladistic analysis of some Hirnantian (latest Ordovician) and Rhuddanian–Aeronian (early Silurian) biserial graptolites and basal monograptids has been undertaken in order to test hypotheses of the relationships among the Neograptina (‘normalograptids’ and their descendents) and to provide a phylogenetic framework for understanding the early Silurian adaptive radiation of graptoloids. It is clear that Silurian graptolite faunas are dominated by two major clades, here named the superfamilies Retiolitoidea and Monograptoidea. Several other lineages whose basal relationships are unresolved, including Normalograptus and Metaclimacograptus , persisted through much of the Llandovery. The Retiolitoidea includes some taxa previously assigned to the Normalograptidae, as well as petalolithids and retiolitids. The Monograptoidea includes akidograptids, dimorphograptids, the uniserial monograptids, as well as stem taxa previously regarded as normalograptids. Both of these major clades had their origins in Late Ordovician time and began their diversification within the Hirnantian–early Rhuddanian, in step with the two main phases of the Hirnantian Mass Extinction. The Neograptina also exhibit an additional interval of accelerated turnover in the Rhuddanian during which the characteristic Silurian fauna largely replaced the Hirnantian Neograptina. One new family, Neodiplograptidae, and four new genera are described: Avitograptus , Rickardsograptus , Korenograptus and Paramplexograptus .
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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 | 0.000 | 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) | 0.001 | 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".