Taxonomic review and phylogenetic analysis of genera Homoeomma Ausserer, 1871 (Araneae, Theraphosidae)

Author(s)

Flávio Uemori Yamamoto

• Document type: Master's Dissertation
• Press: São Paulo. , ilustrações.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2008-10-08

Examining board members

Antonio Domingos Brescovit; Cristina Anne Rheims; Ricardo Pinto da Rocha

• Advisor: Antonio Domingos Brescovit
• Field of knowledge: Biological Sciences - Zoology
• Indexed in: Banco de Dados Bibliográficos da USP-DEDALUS; Biblioteca Digital de Teses e Dissertações - USP
• Location: Universidade de São Paulo. Biblioteca do Instituto de Biociências

Abstract

Theraphosidae is the larger family within suborder Mygalomorphae, with 112 genera and 908 species. It is considered a monophyletic group, divided into nine subfamilies. The subfamily Theraphosinae is restricted to America continent. It is characterized by the presence of a papal bulb with wide and thick embulus presenting keels, wide subtegulum, extending down the bulb to half of tegulum length and by the presence of urticating hairs type I, III and IV. The present work aims the increase of the taxonomic and phylogenetic subfamily knowledge, throughout the study of Homoeomma genera Ausserer, 1871. Homoeomma was revised in 1972, including ten species on it. Nowadays, the genera has 14 species, with distribution restricted to South America (Argentina, Brazil, Colombia, Peru e Uruguay). The Homoeomma pictum holotype presents copulatory bulb and tibial apophysis of leg I that resemble Thrixopelma, so the species is transfered to these genus. The type of Homoeomma peruvianum was also examined and probably do not belong to the genus. Unfortunately, it was not possible to establish a new genus to this species. H. nigrum´s holotype, a female presenting a severed spermathecae, wasn\'t examined. These two species are considered species inquireda. H. stradlingi e H. strabo are established as junior-synonyms of H. familiare. And Homoeomma hirsutum is considered junior-synonym of. 7 The eight remaining species of Homoeomma were included in cladistic analysis, enclosed with Grammostola mollicoma, Magulla obesa, Maraca cabocla, Plesiopelma flavohirtum, P. longisternalis, Tmesiphantes nubilus, Gen. n. sp.1. Oligoxytre caatinga (subfamily Ischnocolinae) was used to set the root. The analysis resulted in two equally parsimonic trees, with 73 steps. The strict consensus (75 steps) presents this topology: (Oligoxystre caatinga ((((Homoeomma stradlingi (H. montanum (H. brasilianum (H. uruguayensis (H. elegans H. villosum)))))(Maraca humile Maraca cabocla ))(Plesiopelma longisternalis Cyriocosmus ritae (Gen. n. simoni Gen. n. sp1 Gen. n. flavohirtum )))(Tmesiphantes nubilus (Grammostola mollicoma Magulla obesa )))). The eight species of Homoeomma do not form a monophyletic group. Three transferences are proposed: Homoeomma simoni and Plesiopelma flavohirtum are transfered to a new genus, with a new species. Gen. N. is well supported by four synapomorphies. H. humile is the sister group of Maraca cabocla, sharing three non exclusive synapomorphies. The genus Maraca is considered sister group of Homoeomma. The six remaining species of Homoeomma form a monophyletic group with three non exclusive synapomorphies: a big papal bulb digitform apophysis, a 90º-135ºangle between embulus and bulb and males metatarsus I presenting a basal curvature. The females of H. brasilianum e H. elegans are described for the first time. Species distribution is updated and enlarged with new records. (AU)