New tribe-level classification of Hypostominae (Loricariidae) based on optimization of morphological states on DNA-based relationships, with descriptions of three new tribes and two new genera
Bibliographic record
Abstract
Abstract Hypostominae tribe-level taxonomy is revised with new recognition and cladistic diagnoses of previously proposed family-level names for the Acanthicus (Acanthicini), Chaetostoma (Chaetostomatini), and Hemiancistrus (Spectracanthicini) clades. Three new tribes are described for the Peckoltia, Pseudancistrus,and ‘Pseudancistrus’ clades, with a new tribe erected for two new monotypic genera containing the sister species ‘Pseudancistrus’ sidereus and ‘P.’ pectegenitor. This third new tribe is known only from the upper Orinoco and Negro Rivers and is identifiable by having an accentuated keel on the caudal peduncle formed by dorsal laminae of the ventral plate series being strongly concave. The new genera are distinguishable by ‘P.’ pectegenitor having extremely long cheek odontodes reaching to the third plate of midventral plate series (vs. anterior to opercular opening in ‘P.’ sidereus) and 10 (vs. 7) branched dorsal-fin rays. We re-optimized morphological character-state change by mapping states previously used to infer evolutionary history onto a composite phylogenetic tree inferred from DNA-sequence data. This revealed the strong influence on morphology-based phylogenies of a correlated suite of opercular character states related to the mechanism for cheek odontode eversion. These states appear to be plesiomorphic within Hypostominae and to have been independently lost or reduced multiple times.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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 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".