Phylogenetic Relationships of the Subclass Peniculia (Oligohymenophorea, Ciliophora) Inferred from Small Subunit rRNA Gene Sequences
Bibliographic record
Abstract
Peniculine ciliates have been recognized as a distinct higher taxon of ciliates for almost 50 years. However, phylogenetic relationships within the Subclass Peniculia are still unsettled. To contribute to our understanding of their phylogeny and provide evidence for the position of Urocentrum turbo, we sequenced its small subunit (SS) rRNA gene and the SSrRNA genes from Lembadion bullinum, Frontonia sp., Paramecium caudatum, Paramecium multimicronucleatum, Paramecium putrinum, and Paramecium woodruffi. Urocentrum turbo was the only one of these species not to exhibit a shortened Helix E10_1, which we conclude characterizes the "higher" peniculines. Except for U. turbo, the peniculines are strongly supported as a monophyletic clade with Lembadion, Frontonia, and Paramecium species forming separate and strongly supported clades by bootstrap analysis using distance matrix, maximum parsimony, and maximum likelihood methods. Urocentrum turbo is associated with different lineages, depending upon the analysis used. The Paramecium species form at least four clades with the Paramecium aurelia subgroup being the most derived. We conclude that the Subclass Peniculia should be divided into two orders, the Order Urocentrida and Order Peniculida, with the latter order having two suborders, the Suborder Frontoniina and Peniculina. We place U. turbo with the peniculines because of shared morphological and stomatogenetic features.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".