New tolbox for undertanding the evolution of Cosmetidae e Metasarcidae: morphology and molecular data (Arachnida: Opiliones: Gonyleptoidea)

• Grant number: 25/03419-0
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Biological Sciences - Zoology - Taxonomy of Recent Groups
• Principal Investigator: Ricardo Pinto da Rocha
• Grantee: Ricardo Pinto da Rocha
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Daniel Nathan Proud

Abstract

Cosmetidae is the most diverse family of Neotropical harvestmen. However the knowledgement of their phylogenetic relationships is unsatisfactory. The main difficulty is related to understanding the limits between supraspecific taxa, which have been largely obscured by the traditional classification system, in which multiple superficial characters were used to propose subfamilies and genera. Although Cosmetidae has been the subject of recent phylogenetic analyzes at the subfamily and family levels, few groups have been studied and resolution of relationships within the family lacks broad taxonomic coverage. Traditionally used morphological characters and gene sequences (e.g. COI, 28S, 18S) have not been sufficiently explored when used alone or in combination. New morphological resources, such as the genital morphology of males, have been explored in order to resolve the classification of groups. However, potentially informative structures such as the ovipositor have been largely neglected and have only recently been studied under comparative approaches for a few species. More robust molecular tools have been needed to resolve phylogenetic relationships in diverse and understudied groups. In this sense, the use of sequences of ultra-conserved elements could clarify the relationships and classification of Cosmetidae at the subfamily level. The present project will develop a phylogenomic analysis of Cosmetidae based on sequences from ultra-conserved regions integrating morphological characters and, for the first time, the ovipositor.Metasarcidae was reviewed recently, However, the ovipositor is unknown and a new hypothesis based on molecular data is wellcome. (AU)