Canthonini (Scarabaeidae: Scarabaeinae) of Gondwana : comparison of male genitalia evolutionary trends and phylogeny
Bibliographic record
Abstract
The current study is about the evolution and the morphology of dung \nbeetles, subfamily Scarabaeinae. The study includes the systematics of the \ntribe Canthonini and an exhaustive analysis of the morphological variation of \nmale genitalia including species from the 11 tribes of the subfamily, mainly \nCanthonini, Ateuchini, Scarabaeini and Coprini. With the aim to go deep in the \nphylogenetic relationships of the tribe Canthonini, the largest of the subfamily \nScarabaeinae, with 91 genera and 875 species, a total of 109 genera, 327 \nspecies and 513 specimens were reviewed. The tribe Canthonini is mainly \ndistributed in Gondwana, with species in America, Africa, Madagascar, \nAustralia, New Zealand and the Oriental region. Species of the different regions \nwere included in the detailed examination of male genitalia as well in the \ncladistic analysis using morphological characters. \nStrong evidence of a need for sub-division of Canthonini in natural \ngroups, morphologically and ecologically more solid groups, is one of the main \nresults obtained. Three tribes are proposed, the tribe Byrrhidiini (Byrrhidium, \nDicranocara, Namakwanus, and Versicorpus), tribe Circelliini (monotypic genus \nCircellium), and the tribe Canthonini, firstly with the American genera (Canthon, \nMalagoniella, Megathopa, Megathoposoma, Eudinopus, Canthonidia, \nTetraechma, Anisocanthon, Melanocanthon, Sylvicanthon, and Hansreia), as \nwell as the African genera Gyronotus and Anachalcos. Genera from \nMadagascar, Australia and the Oriental region should be treated in separate \nanalyses, and probably the pre-established tribes such as Panelini, Epilissini \nand Mentophilini, could acquire validity in the context of a new classification for \nthese groups currently in Canthonini. \nThe phylogeny of the genus Epirinus and description of six new species \nis also presented. Epirinus is a monophyletic group, although by morphological \ndifferences, is not considered under the tribe Canthonini. Equally the genus \nDeltochilum is not considered as part of the tribe Canthonini, since in the \nphylogenetic analysis of American genera, Deltochilum appear polyphyletic, and this genus deserves a more detailed analysis of its systematics and \nclassification. \nPatterns of variation in the genitalia structures, mainly the sclerites, were \nuseful in species separation and to define genera. However, the patterns were \nnot so suitable in setting the limits of the tribes. To date, taxonomists have been \ntrying to fit the whole range of variation in species and genera into a preestablished \nand limited Scarabaeinae tribal classification. Based on this study \nthe recommendation for a better understanding of the evolutionary history, and \nto improve the taxonomic classification of the tribe Canthonini and the \nScarabaeinae dung beetles, is to study in detail each group, in morphological, \nmolecular and even ecological and biogeographical aspects. Information from \nthese different approaches, will help to establish the borders for the tribes, and \ntherefore to have more accurate classifications.
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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 | 0.000 |
| 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".