A new family of Cypriniformes (Teleostei, Ostariophysi) based on a redescription of †<i>Jianghanichthys hubeiensis</i>(Lei, 1977) from the Eocene Yangxi Formation of China
Bibliographic record
Abstract
The fossil cypriniform fish †Jianghanichthys hubeiensis from Eocene mudstones in Songzi, Hubei, China, was originally assigned to the extant cyprinid genus Osteochilus, then later to the new genus †Jianghanichthys by its original author, but with its familial status uncertain. Other authors subsequently assigned it to the cypriniform family Catostomidae. A detailed comparison of osteological characters shows that †Jianghanichthys is distinguished from all other cypriniforms by having (1) first principal anal fin ray branched; (2) supraorbital sensory canal largely exposed in frontal but roofed by longitudinal flange; (3) supraorbital sensory canal meeting the temporal sensory canal within the parietal; (4) maxilla bearing three dorsal processes; (5) dorsal surface of anterior end of dentary triangular and broad; and (6) the first centrum of †Jianghanichthys has a similar size and prominent posterior concavity to the second centrum. A computed tomography (CT) scan of a matrix-covered skull confirmed these unique characters, as well as that the pharyngeal teeth are either absent or not well formed. A series of phylogenetic analyses, using parsimony criteria and morphological characters, consistently recovers †Jianghanichthys in a polytomy with the non-loach cypriniform families, but it could not be placed within any recent family. Among osteological characters, few unique synapomorphies are shared by Jianghanichthys and recent families of Cypriniformes, whereas a large number of symplesiomorphies with the Catostomidae, Cyprinidae, and Gyrinocheilidae were found, indicating that Jianghanichthys is a stem taxon of Cypriniformes. Therefore, the first family of Cypriniformes known only from fossils, †Jianghanichthyidae, is erected to contain this Eocene cypriniform fish. http://zoobank.org/urn:lsid:zoobank.org:pub:42C2E6E4-9E85-406B-A892-8998735F200DCitation for this article: Liu, J., M.-M. Chang, M. V. H. Wilson, and A. M. Murray. 2015. A new family of Cypriniformes (Teleostei, Ostariophysi) based on a redescription of †Jianghanichthys hubeiensis (Lei, 1977) from the Eocene Yangxi Formation of China. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1004073.
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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 | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| 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".