Friday, October 27, 2023

[Arachnida • 2023] Acanthogonatus messii • A New small Acanthogonatus Karsch, 1880 (Mygalomorphae: Pycnothelidae) Species from Argentinean Patagonia, and its phylogenetic placement


Acanthogonatus messii Signorotto & Ferretti,  

in Signorotto, Mancini et Ferretti, 2023. 
 
A new Pycnothelidae Chamberlin, 1917 species from Patagonian steppe, Chubut, Argentina is ­described and illustrated. Acanthogonatus messii Signorotto & Ferretti n. sp. differs from the remaining species of the genus by the male palpal bulb with a narrow basal portion and keel of embolus slightly-developed in conjuction with the presence of strong spines on ventral metatarsus I, females having spermathecae with short oval receptacles, and digitiform internal expansions arising from their base. This comprises a small species that construct burrows on sandy open environments with small shrubs. Results from phylogenetic analysis showed that is close to A. birabeni Goloboff, 1995 and A. chilechico Goloboff, 1995 inside the “patagonicus” group.

KEYWORDS: Araneae, patagonic steppe, cladistic, new species

Acanthogonatus messii Signorotto & Ferretti n. sp., habitus:
A, female molted in laboratory; B, female collected and photographed from field;
C, male molted in laboratory; D, male collected walking in the field.
Scale bars: 1 cm.

  A, habitat at type locality of Acanthogonatus messii Signorotto & Ferretti n. sp.;
B, C, female burrows opened at night at type locality.

Acanthogonatus messii Signorotto & Ferretti n. sp.

DIAGNOSIS. — Males can be distinguished from the known species, excepting A. chilechico , by the palpal bulb, with basal portion narrower and keel of embolus slightly-developed ( Fig. 4  A-D), and by the presence of strong spines on ventral metatarsus I ( Fig. 3H, I  ). Males differ from those of A. chilechico by the presence of labial cuspules ( Fig. 3E  ) and from A. birabeni by the presence of strong spines on ventral metatarsus I ( Fig. 3H, I  ). Males resemble those of A. notatus by the coloration with dark chevron on dorsal abdomen ( Fig. 3C  ), but can be distinguished by the curved embolus without small teeth on apical region ( Fig. 4C  ) and presence of strong spines on ventral metatarsus I ( Fig. 3I  ). Females differ from the known species of the genus by the shape of the spermathecae, with short oval receptacles, and digitiform internal expansions from their base ( Fig. 5H  ).

ETYMOLOGY. — The specific name is a patronym in honor of Lionel Andrés Messi, an Argentine professional footballer and one of the greatest players of all times, unique winner of seven Ballons d’or.


Fiorella SIGNOROTTO, Mariana MANCINI and Nelson E. FERRETTI. 2023. A New small Acanthogonatus Karsch, 1880 (Mygalomorphae, Pycnothelidae) Species from Argentinean Patagonia: Description of A. messii Signorotto & Ferretti n. sp. and its phylogenetic placement