A new species of catfish (Claroteidae, <i>Chrysichthys</i>) from an Eocene crater lake in East Africa
Bibliographic record
Abstract
Several specimens of a fossil catfish, collected from the Eocene Mahenge site of Tanzania, are identified as a member of Chrysichthys (Claroteidae) based on several features, including long, thick pectoral and dorsal spines and the presence of nasal barbels. The fossil fish is described as a new species based on unique characters (e.g., 20 principal caudal fin rays). The fossil record of Siluriformes in Africa includes few articulated skeletons; isolated spines or crania are more common. Although several African Eocene catfish crania previously have been described in their own genera, the Mahenge specimens preserve details that indicate their relationship to the living genus Chrysichthys, and therefore the new species is included in that genus instead of being given its own. Previously, the oldest record for Chrysichthys was from the Pliocene; these specimens extend the range of Chrysichthys back to the Eocene. The Mahenge locality itself is significant because it contributes knowledge of the poorly known sub-Saharan Eocene fauna and flora.
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 | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 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".