Divergence time analyses suggest a Miocene origin of the narrow Amazonian endemic rheophytic Ceratolejeunea temnantha (Spruce) Reiner-Drehwald (Porellales, Lejeuneaceae)
Bibliographic record
Abstract
The recent rediscovery of the rheophytic endemic Ceratolejeunea temnantha ~130 years after its original description, on the upper Rio Negro in the Brazilian Amazon, has enabled the assessment of its enigmatic phylogenetic position, estimates of its divergence time, and updates on its distribution and potential habitat threats. Phylogenetic analyses strongly supported its placement in the genus Ceratolejeunea in a geographically disparate clade including a Madagascar endemic C. saroltae and two Neotropical taxa, C. confusa and C. caducifolia. Divergence time estimates date the clade’s stem age to the late Miocene (8.92 [HPD: 12.39–6.04] Ma) offering further evidence that the evolution of rheophytes in northern South America is correlated with the expansion of cryptogams into novel ecological niches promoted by dramatic landscape changes during the Miocene. Major geomorphological and hydrological transformations contributing to such diversification are most likely the changing dynamics of the inundated mega lake system to the establishment of the Amazon River due to the Andean orogeny and the subsequent cessation of marine influences in the north-western portion of the Basin. Until recently, this rheophyte of seasonally inundated black-water forests was only known from its type collection from the Rio Negro near São Gabriel da Cachoeira (Brazil) as described by Richard Spruce in 1884. These new collections extend the distribution of this rare narrow endemic to the middle Rio Uaupés, a tributary of the upper Rio Negro near the Columbian border.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".