A new genus of Stygninae from a relictual rainforest in CearĂ¡, northeastern Brazil (Opiliones, Laniatores, Stygnidae)
Author
Kury, Adriano B.
text
Zootaxa
2009
2057
63
68
journal article
10.5281/zenodo.186714
b366327b-fdcf-469d-815d-2f49d14f9ea0
1175-5326
186714
Ricstygnus
gen. nov.
Etymology.
The genus name is a composite of
Ric
, a homage to my friend Ricardo Pinto-da-Rocha, who published the only monographic treatment of the
Stygnidae
to date, plus
Stygnus
, the
type
genus of the family, and should be treated as being masculine in gender.
Type
species.
Ricstygnus quineti
sp. nov.
Diagnosis.
Differs from all other Stygninae by: (1) presence of dorso-basal hollow in ventral plate containing a multiply folded haematodocha (instead of absence); (2) distal part of ventral plate forming roof with 2 straight prongs (instead of smooth, without roof); (3) intermediate setae of ventral plate short and situated dorsally (instead of usually long and laterally placed, but see Pinto-da Rocha, 1997 figs. 574 and 577 for exceptions in
Sickesia
and
Protimesius
); (4) scutal armature consisting of 1 pair of paramedian acuminate tubercles on each area III to posterior margin (instead of 1 pair of tubercles on area III); (5) main armature consisting of 1 pair of paramedian acuminate spines on free tergite I (instead of armature of free tergites stouter at free tergite III); (6) scutum outline subtrapezoid, widest at posterior border with 2 constrictions (instead of subrectangular, narrowest at posterior border); (7) carapace as long as abdominal scutum (instead of clearly shorter); and (8) scutal groove deeply projected into area I separating it into 2 triangular halves and reaching groove II (instead of not reaching groove 2 and causing much smaller deformation of area I). The combination of (9) presence of cornute macrosetae, consisting of 3 pairs of large, flattened curved distal macrosetae of ventral plate and (10) basal setae of ventral plate clearly transverse instead of oblique, relates
Ricstygnus
gen. nov.
to
Stygnus
,
Sickesia
(distal macrosetae normal) and
Pickeliana
. The presence of interocular stout spine (11) suggests that it is probably closest to
Stygnus
and
Sickesia
.