Historical biogeography of the palaeoendemic toad genus <i>Oreophrynella</i> (Amphibia: Bufonidae) sheds a new light on the origin of the Pantepui endemic terrestrial biota
Bibliographic record
Abstract
Abstract Aim Using the Pantepui palaeoendemic toad genus Oreophrynella, we explored (1) the origin of Pantepui endemism and the hypothesis of Pantepui being a source of diversity for the surrounding areas, including the geologically younger Andes; (2) whether early diversification of Oreophrynella conforms with that of Stefania (Hemiphractidae), another Pantepui endemic amphibian, which was recently shown to have vicariantly diverged from Pantepui highlands widespread Oligocene ancestors. Location The fractured island‐like topography of the Pantepui biogeographical region in north‐eastern South America. Methods We inferred the molecular phylogeny of Oreophrynella and other “basal” Bufonidae genera using three mitochondrial and two nuclear DNA sequences under Bayesian and maximum likelihood methods. We estimated divergence times using a relaxed‐clock model and reconstructed ancestral areas through multiple models in a common likelihood framework. Results Phylogenetic analyses recovered a monophyletic Oreophrynella sister to Atelopus. Biogeographical analyses strongly suggested colonization of Pantepui via a pre‐Miocene (Eocene/Oligocene) long‐distance dispersal of a proto‐Andean ancestor, followed by pre‐Quaternary (lower Miocene) vicariant divergences of main lineages, and endemism of these main lineages to distinct biogeographical subunits. Main conclusions Our results suggest that at least part of the Pantepui diversity stemmed from dispersals from the proto‐Andes. Three hypotheses emerge for the origin and evolution of Pantepui endemism, the Distance Dispersal theory, the Plateau theory and the Disturbance–Vicariance theory. Our results indicate that the early diversification of Oreophrynella conforms to that of Stefania, but hint at different factors responsible for the survival or extinction of different tepui summit amphibians.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".