Metalibitia

Coronato-Ribeiro, Amanda & Pinto-Da-Rocha, Ricardo, 2017, Taxonomic revision and cladistic analysis of the genus Metalibitia Roewer, 1912 (Opiliones, Cosmetidae, Cosmetinae), Zootaxa 4291 (2), pp. 201-242 : 237

Metalibitia monophyly and interspecific relationships

The monophyly oF the genus Metalibitia is supported by three unambiguous synapomorphies, all From penis morphology, and has a Goodman-Bremer support oF two. One oF these synapomorphies is the presence oF a Folded membranous extension on the latero-median region oF the ventral plate. This structure, oF unknown Function, is present in all species oF Metalibitia and in no other cosmetid, although it varies in size oF projection From the lateral sides. Another Feature, not shared by any other cosmetid genera, is the insertion oF the glans at the middle region oF the ventral plate (at the base in other cosmetids). This Feature is an autapomorphy oF the genus, and is interpreted to be reverted in Metalibitia santaremis . The third deFining apomorphy is the presence oF straight macrosetae C on lateral margin oF ventral plate.

Within the genus, M. adunca is sister to two species groups (with Four species each); together, they Form a clade supported by the contiguous dorsal tubercles on the pedipalpal Femur (character 21, state 1). Both clades have a low Goodman-Bremer support oF one. One clade is composed oF M. brasiliensis , M. rosascostai , M. santaremis and M. abuna sp. nov., and is supported by the presence oF Four-Five tubercles on trochanter IV, among other Features (see Table 3). Within this clade arise a pair oF sister-species ( M. santaremis and M. abuna sp. nov.) oF Amazonian distribution, contrasting with the other species oF the genus that occur in open vegetation in southern South America. However, both species occur in areas currently covered by savanna or that were once covered by savanna during the Pleistocene ( Cohen et al. 2014). The other Amazonian species, M. fuscumaculata , was not included in the analysis because it is known From only one Female specimen. We could postulate, based on geographical distribution, that it is related to the Amazonian clade. However, the one character that is not related to genus, the conspicuous armature oF Free tergite III with high tubercle, is not observed in M. fuscumaculata . The other species group is composed oF M. paraguayensis , M. borellii , M. tibialis , and M. argentina and is supported by the presence oF a high number oF tubercles on the dorsal scutum oF the body and by the smooth apex oF penial stylus.