A new species of claroteid catfish (Siluriformes: Claroteidae) from the Eocene of Egypt, (Africa) indicates continental differences in tempo of catfish evolution
Bibliographic record
Abstract
We here describe a fossil catfish from freshwater deposits of the Jbel Qatrani Formation of the Fayum Depression, Egypt, as a new species of an extant genus, †Clarotes eocenicus, sp. nov., in the family Claroteidae. We base this placement on several cranial osteological features, including robust, laterally oriented anterior cornua of the mesethmoid, cranial fontanelle formed in mesethmoid and frontals but not extending into the parieto-supraoccipital, dermal ornamentation of small bumps concentrated on the posterior part of the skull, and supraoccipital crest short and broadly triangular. The material comes from the upper Eocene L-41 locality, which represents deposition in an oxbow lake environment. The new taxon, along with a previously described catfish from Tanzania, indicate that claroteid catfishes were established in both North and East Africa in the Eocene, and, unlike North America, Europe and Asia in which modern genera of catfishes were not present in the Eocene, at least two extant catfish genera had already evolved in the fresh waters of Africa by 45–35 million years ago.
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".