20th International Congress of Arachnology

DENVER MUSEUM OF NATURE & SCIENCE

REPORTS

No. 3, July 2, 2016

International Congress of Arachnology

they lacked good taxon representation at the family level.

Here we analyzed a set of the 14 existing transcriptomes

with 44 additional ones, representing 82% of the extant

familial diversity in Opiliones. Our phylogenetic analy-

ses, including a set of data matrices with different gene

occupancy and evolutionary rates and using a multitude

of methods correcting for a diversity of factors in phyloge-

nomic data matrices, provide a robust and stable Opiliones

tree of life, where most families are precisely placed. Our

dating analyses and biogeographic analyses using alterna-

tive calibration points, methods, and analytical parameters

provide well-resolved divergences, consistent with two main

scenarios. A pattern of Temperate Gondwanan groups split-

ting first from the rest of the taxa (Laurasia and Tropical

Gondwana), before the breakup of Pangea, suggests ancient

regionalization in Pangea. Other groups however show a

more recent split between Laurasian and Gondwanan taxa,

roughly coincident with the time of Pangean breakup, and

thus being consistent with a hypothesis of Pangean vicari-

ance. The integration of recent fossil taxa and au currant

geological reconstructions with broad taxonomic sampling

of extant harvestmen demonstrates the broad utility of

Opiliones lineages as models for examining ancient biogeo-

graphic processes.

Keywords: Opiliones, systematics, transcriptomics,

phylogenomics, biogeography

Student - oral presentation

A light in the end of the “funnel”:

preliminary results on the phylogeny of

Segestriidae (Araneae, Synspermiata,

Dysderoidea)

André Marsola Giroti

1, 2

, Antonio Domingos Brescovit

Laboratório Especial de Coleções Zoológicas, Instituto

Butantan, Avenida Vital Brazil, 1500, 05503-900, São

Paulo, Brazil;

Departamento de Zoologia, Instituto

de Biociências, Universidade de São Paulo, Rua do

Matão, trav. 14, 101, 05508-090, São Paulo, Brazil

giroti.am@usp.br

Currently, Segestriidae Simon, 1893 is composed by four

taxonomically valid genera which comprises 120 described

species:

Segestria

Latreille, 1804,

Ariadna

Audouin, 1826,

Gippsicola

Hogg, 1900 and

Citharoceps

Chamberlin, 1924.

Segestriidae is part of the Dysderoidea clade, together

with Dysderidae, Orsolobidae and Oonopidae. Later

cladistic analysis involving Segestriidae focused only on

the Dysderoidea clade and the relationships among its

families. We present the first results on the phylogeny of

Segestriidae genera, also including representatives of the

currently synonymized ones, aiming to test the hypothesis

of monophyly of the family and its genera. The data matrix

was build based on the codification of 119 morphological

characters in 41 terminals belonging to Segestriidae, the

other Dysderoidea families, and Caponiidae as the root.

The analysis was performed by TNT 1.1 under parsimony

and equal weights. We retrieved two most-parsimonious

trees with 206 steps (CI = 69; RI = 88), with the strict

consensus collapsing only one branch (207 steps; CI =

69; RI = 88). The results show Segestriidae as a mono-

phyletic clade, sister group of (Orsolobidae (Oonopidae +

Dysderidae)), differing from previous resolutions of the

Dysderoidea clade. Within Segestriidae, we can identify

two subfamilies: Segestriinae Simon, 1893, comprising the

paraphyletic

Segestria

Gippsicola

and Segestriinae AFR sp.

1, and Ariadninae Wunderlich, 2004, composed by

Ariadna

(lato and strictu sensu),

Citharoceps

, and a clade with

Ariadninae AFR sp. 1, Ariadninae AFR sp. 2 and Ariadninae

AME sp. 1, representing a possible new genus. This study

will continue with the future addition of more Segestriidae

terminals, aiming to achieve a better resolution, mainly on

the Ariadninae clade.

Keywords: cladistics, Haplogynae, morphology, systematics

Student - poster presentation

Male chemosensory scopulae in Segestri-

idae (Araneae): morphology and biological

aspects in

Ariadna

Audouin species

*André Marsola Giroti

1,2

, Antonio Domingos Brescovit