Morphological phylogenetic analysis of the spider genus Physocyclus (Araneae: Pholcidae)
Por:
Valdez-Mondragon, A
Publicada:
1 ene 2013
Categoría:
Insect Science
Resumen:
With 30 species and a natural distribution in North America, 28 confined
to Mexico, Physocyclus Simon 1893 is the most diverse genus within the
pholcid spider subfamily Arteminae. This paper provides the first
phylogenetic test of the genus's monophyly through a cladistic analysis
of 54 morphological characters using equal and implied weighting. The
equally weighted analysis found 12 most parsimonious trees, whereas the
analysis with implied weights varying the concavity values (K = 6-10)
found five or six most parsimonious trees. The monophyly of the genus
Physocyclus is supported by three synaphomorphies: 1) the paired ventral
apophysis on the anterior part of the epigynum; 2) the lateral
constraints in the middle part of the epigynum; and 3) the arc of the
uterus, with a single sclerotized projection on the anterior part. The
genus Physocyclus contains two clades treated as species groups: the
globosus group, with 11 species, and the dugesi group with 19 species.
The species relationships within the globosus group were better resolved
than those in the dugesi group. The globosus group has a biogeographical
distribution pattern in the Mesoamerican and Mexican Mountain biotic
components, whereas the dugesi group has a distribution pattern in the
Mesoamerican and Continental Nearctic biotic components. Given the
complex biogeography in Mexico, apparently a large-scale vicariant event
separated the two major clades within the genus Physocyclus.
Filiaciones:
UNAM, Inst Biol, Dept Zool, Colecc Nacl Aracnidos CNAN, Coyoacan 04510, DF, Mexico
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