RESUMO
The genus Scelimena Serville (Orthoptera: Tetrigidae) from China is reviewed. One species, Scelimenaspicupennis Zheng & Ou, 2003 (China: Yunnan) is redescribed, and a new record of Scelimenadiscalis (Hancock, 1915) from China is given. An annotated identification key for Chinese species of the genus Scelimena is provided. Mitochondrial genes of S.spicupennis and S.discalis were sequenced and annotated. The sizes of the two sequenced mitogenomes are 17,552 bp (S.discalis), and 16,069 bp (S.spicupennis), respectively. All of the PCGs started with the typical ATN (ATT, ATC or ATG) or TTG codon and most ended with complete TAA or TAG codon, with the exception of the ND5 gene, which terminated with an incomplete T. The mitochondrial genomes for these two recorded species are provided, and the constructed phylogenetic tree supports their morphological taxonomic classification. The topology of the phylogenetic tree showed that three species of Scelimena were clustered into one branch and formed a monophyletic and a holophyletic group.
RESUMO
The phylogenetic relationships of bandicoots and bilbies have been somewhat problematic, with conflicting results between morphological work and molecular data. This conflict makes it difficult to assess the taxonomic status of species and subspecies within this order, and also prevents accurate evolutionary assessments. Here, we present a new total evidence analysis, combining the latest cranio-dental morphological matrix containing both modern and fossil taxa, with molecular data from GenBank. Several subspecies were scored in the morphological dataset to match the molecular data available. Both parsimony and Bayesian analyses were performed, giving similar topologies except for the position of four fossil taxa. Total evidence dating places the peramelemorphian crown origin close to the Oligocene/Miocene boundary, and the radiations of most modern genera beginning in the Late Miocene or Early Pliocene. Our results show that some species and subspecies require taxonomic reassessment, and are revised here. We also describe a new, extinct species from the Nullarbor region. This suggests that the number of recently extinct peramelemorphian species is likely to further increase.
Assuntos
Marsupiais , Animais , Teorema de Bayes , Evolução Biológica , Fósseis , FilogeniaRESUMO
The early stages of phylogenetic inference from morphological data involve a sequence of choices about which analytical methods to employ. At each stage, the selection of one method over another can dramatically impact tree inference. Phylogenetic hypotheses are sensitive to decisions relating to which taxa and characters to select for analysis, whether and how to delimit character states, which taxa to use as outgroups, and how to account for character dependence. Using extant hominoids as a test case, I quantify the degree to which phylogenetic inferences are sensitive to the choice of method used to transform continuously scaled variables into categorical traits. I demonstrate that the character coding strategy significantly impacts hypotheses of character state identity and phylogenetic branching patterns. To avoid biasing evolutionary hypotheses, I recommend that continuously scaled characters be analyzed without prior discretization.