First record of Travunioidea (Arachnida: Opiliones: Laniatores) from China, with the description of a new monotypic genus from a cave
Author
Zhang, Chao
The Key Laboratory of Invertebrate Systematics and Application, Institute of Life Science and Green Development, College of Life Sciences, Hebei University, Baoding, Hebei 071002, China.
Author
Derkarabetian, Shahan
0000-0002-9163-9277
Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. sderkarabetian @ gmail. com; https: // orcid. org / 0000 - 0002 - 9163 - 9277
sderkarabetian@gmail.com
text
Zootaxa
2021
2021-06-10
4984
1
87
97
journal article
4955
10.11646/zootaxa.4984.1.8
71b1cbb5-3e51-4125-93de-a1af8fc9e2c3
1175-5326
4928651
9D5096C6-EB6F-425C-B982-634792B54E84
Sinonychia
gen. n.
Figs 1–31
,
33
ZooBank LSID:
urn:lsid:zoobank.org:act:
3E5B75D9-94F0-4B4E-8D09-89A5A916495C
Type
species:
Sinonychia martensi
sp. n.
Diagnosis.
Sinonychia
gen. n.
can be differentiated from all other
Cladonychiidae
genera on the basis of penis morphology, having a combination of two pairs of relatively thick lateral setae on the glans, a cylindrical, basally widening glans, and an elongate stylus arising apically. Morphologically the new genus is most similar to
Speleonychia
from the Pacific Northwest of North America but can be distinguished by several characters. First, in spination of the penis: in
Sinonychia
gen. n.
two pairs of apical setae on the penis are thick and at a 90˚ or larger angle to the stylus, whereas in
Speleonychia
these setae are at a much smaller angle, directed apicad (
Briggs 1974
: figs 7–8). Second, the shape of the glans: in
Sinonychia
gen. n.
the glans is almost cylindrical, with a wide, blunt apex and with the stylus arising sub-terminally, while in
Speleonychia
the glans is more triangular, with a more pointed apex and a stylus arising terminally. Third, in spination of the pedipalpal femur:
Sinonychia
gen. n.
has multiple distal SBTs on the ventral surface at the distal end (
Figs 5–6
), while
Speleonychia
has only a single SBT (
Briggs 1974
: fig. 2).
Etymology.
The generic name is composed of “Sino”, derived from the Latin word “Sinae” (from the Ancient Greek “Σῖναι”) which generally refers to
China
, and of the Latin noun “onyx” (from the Ancient Greek “ὄνῠχος”) meaning ‘claw’, a common name applied to many travunioid and triaenonychoid genera. The second part of the new genus name also indicates morphological similarity with the genus
Speleonychia
. The genus name is feminine.
Description.
Highly troglomorphic with unpigmented body (
Figs 22–31
). Ocularium greatly reduced in size, smooth, set back from anterior margin of carapace; eyes and retinae completely absent (
Figs 1
,
22–31
). Dorsal scutum of the “eta” (η) category of
Kury & Medrano (2016)
. Genital operculum nearly triangular (
Fig. 9
). Sternum elongate and narrowly triangular (
Fig. 8
). Pedipalps thin, elongate, lacking pigment, with thin SBTs (
Figs 5–6
). Legs extremely long, thin, and lacking pigment. Claws III–IV with peltonychium (
Figs 10–13
). Penis truncus thin and elongate, musculature restricted to its base (
Fig. 16
); glans articulated with truncus, with two pairs of setae, the more distal pair being smaller than the other pair; stylus elongate, arising apically from glans (
Figs 17–19
).