A large, freshwater chanid fish (Ostariophysi: Gonorynchiformes) from the Upper Cretaceous of Madagascar
Bibliographic record
Abstract
Isolated fossil bones from freshwater Upper Cretaceous (Maastrichtian) deposits in the Mahajanga Basin of northwestern Madagascar are identified as belonging to a gonorynchiform fish. Multiple elements representing the same bone, including opercles, hyomandibulae, frontals, and basioccipitals, indicate that only a single gonorynchiform species is present. The most diagnostic element is here named as a new genus and species, †Vango fahiny; the other elements likely belong to the same taxon. The Madagascan gonorynchiform material shares features with members of the subfamily Chaninae and is assigned to that group. It is similar to the extant milkfish Chanos chanos but can be easily distinguished from that species by numerous features, such as the basioccipital and maxilla being relatively shorter than those of C. chanos, and the opercle being overall rounder and having a shorter auricular process. The presence of a chanid in Madagascar in the Maastrichtian most likely represents an invasion of a marine lineage into fresh waters. The previously known Cretaceous fossils of gonorynchiforms are spread throughout the Tethys Sea in mid-latitude to northern regions from the east (e.g., Lebanon, Europe) through to the southwest (e.g., Mexico, Brazil). †Vango faniny gen. et sp. nov. represents the first Mesozoic/Paleogene record of gonorynchiforms in East Gondwana, comprising primarily Antarctica, Australia, Madagascar, and the Indian subcontinent.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| 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".