Stellantia Armbruster & Lujan 2024, new genus
Bibliographic record
Abstract
Stellantia Armbruster & Lujan, new genus urn:lsid:zoobank.org:act: 894AA6EB-3851-4EA7-B4FB-24724F2A0491 (Figs. 1B, 2B) Type-species. Pseudancistrus sidereus Armbruster, 2004b Included species. Pseudancistrus sidereus Armbruster, 2004b:8, fig. 3. Río Siapa from 10–15 kilometers downstream, Río Casiquiare - Río Negro drainage, 01.50000°, -065.71667°, Río Orinoco drainage, Amazonas, Venezuela. Phylogenetic diagnosis. Reversal to large interhyal (27: 1>0), tall walls of metapterygoid channel (56: 0>1), reversal to narrow quadrate (64: 1>0), loss of flap of quadrate extending below symplectic foramen (66: 1>0), reversal to two to four cheek plates between canal plate and opercle (88: 3>2); no contact between infraorbital 4 and orbit (90: 1>2), anterior margin of mesethmoid flared (102: 0>1), loss of exterior contact between sphenotic and posteriormost infraorbital (117: 0>1), and increase in number of vertebrae to 12–15 from first normal neural spine posterior to dorsal fin up to and excluding the hypural (121:1). Comparative diagnosis. Stellantia is readily identified from all other Hypostominae except Colossimystax by having the dorsal lamina of each ventral plate of the caudal peduncle concave, accentuating the caudal peduncle keel (vs. caudal peduncle ventral plates rounded, lacking concave dorsal lamina, caudal peduncle keel weak or absent); and from Colossimystax by having seven branched dorsal-fin rays (vs. 10). Geographical distribution. Known from main channels of the upper Orinoco River basin upstream of San Fernando de Atabapo, including the lower Ventuari River, and the Casiquiare River basin upstream of its confluence with the Negro River, including the lower Siapa River, exclusively in Amazonas, Venezuela. Description. See Tab. S3 and Armbruster (2004b). Etymology. An abstract, feminine noun modified from the Latin adjective stellans for starry in reference to the dark body with white to yellow spots which appear like a field of stars, a feature that inspired the species epithet as well. Stellantia requires a change of ending for the single species in the genus: Stellantia siderea. Conservation status. Stellantia siderea was evaluated as Least Concern (LC) by the IUCN (Armbruster, 2023b). The species is common throughout its range. Material examined. Río Orinoco drainage, Amazonas, Venezuela. Holotype: MCNG 26125, 175.6 mm SL, Paratypes: AUM 37562, 1, 148.7 mm SL; FMNH 105294, 4, 149.5– 176.7 mm SL; MCNG 48261, 1 c&s, 149.8 mm SL.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.010 | 0.002 |
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".