Revision of the genus Sinopalaeocossus Hong (Hemiptera: Palaeontinidae), with description of a new species from the Middle Jurassic of China
Author
Wang, Bo
Author
Zhang, Haichun
Author
Fang, Yan
Author
Duan, Ye
text
Zootaxa
2006
1349
37
45
journal article
10.5281/zenodo.174498
f99123ac-7aaa-477e-a167-55ff5502c9c0
1175-5326
174498
Sinopalaeocossus trinervus
sp. nov.
Figs. 1–4
Diagnosis.
Fore wing as for genus.
Hind
wing oval; branch
RP
coalesced with M1 at basal 0.35 wing length and for a long distance; branches M3, CuA1 and CuA2 subparallel for distal half; CuP oblique and slightly curved anteriorly; Pcu slightly curved anteriorly and terminally; membrane infuscate with a wide white band in the center.
Description.
Holotype
. Fore wing length
25.1 mm
, width
13.9 mm
. Vein ScA nebulous. Vein ScP arising basally, with several obscure branches (about four in right fore wing), fused with RA at basal 0.25 wing length. Stem R+M a little curved, close to but not coalesced with ScP, connected to CuA by crossvein r+m-cua at basal 0.12 wing length. Vein R departing from stem R+M a little distal of crossvein r+m-cua and running close to ScP. Branch RA free for a very short distance after its departure from R, and then fused with ScP; its remaining part after nodal line subparallel to costal margin, ending in anterior margin near apex of wing. Branch
RP
subparallel to costal margin, connected to M1 by crossvein r-m just distal of the nodal indentation, terminating in apex. Stem M straight, dividing into M1+2 and M3+4 at the same level of R fork. M1+2 bifurcating at the same level of nodal indentation. M3+4 bifurcating at basal 0.32 wing length. M4 geniculate basally, connected to CuA by crossvein m-cua, and then subparallel to M3. Crossvein r+m-cua long, transverse and almost straight. Crossvein m4-cua long, subparallel to costal margin. Cu straight, bifurcating near base. CuA geniculate at junction with m-cua, bifurcating at basal 0.18 wing length. Discal cell length
5.2 mm
, width
2.2 mm
at nodal line; antenodal region square, length
2.2 mm
; postnodal region rhomboid and a little longer than antenodal region. Clavus length
6.8 mm
, width
5.3 mm
. CuP curved anteriorly, terminating at distal end of clavus. Pcu simple. A1 a little curved posteriorly. Nodal line traceable as crease across ScP+RA and
RP
to M just beyond its initial division, and then almost equally separating discal cell into two parts; it continuously crossing m4-cua, following stem CuA and CuA2, and reaching distal end of clavus. Marginal membrane very thin.
Hind
wing length 17.0 mm, width
11.6 mm
, length/width ratio 1.46; costal area wide, length/width ratio 2.76, maximal width in basal 2/5; nodal indentation at basal 0.25 wing length. Sc arising basally, running close to R and coalesced with R at basal 0.18 wing length. Stem R+M forking into R and M at wing base. Vein R a little curved anteriorly, lying alongside Sc until their fusion. Branch Sc+RA1 dividing from Sc+RA at same level of indentation, ending in costal margin distal of indentation. Branch RA2 slightly curved anteriorly, ending in costal margin. Vein
RP
branching from stem R at basal 0.28 wing length, coalesced with M1 at basal 0.35 wing length, and terminating near apex of wing;
RP
+M1 length
1.2 mm
. Stem M bifurcating at basal 0.11 wing length. Branch M1 departing from stem M1+2 at same level of Sc fused with RA, curved anteriorly; branch M2 a little curved terminally; M3+4 close to CuA at one point at basal 0.16 wing length, and then a little curved anteriorly. Stem CuA forking into CuA1 and CuA2 at about basal 0.25 wing length; CuA1 a little curved anteriorly and CuA2 straight. CuP oblique, slightly curved anteriorly. Pcu slightly curved anteriorly and terminally. A1 absent. Marginal membrane very thin.
Legs. Femora and tibiae of left and right forelegs preserved. Fore femur robust and wider than fore tibia; fore tibia slender, 1.5 times as long as fore femur; distal end of fore tibia with row of spines. Tibia of right middle leg preserved.
Paratype
.
Hind
wing, length
23.8 mm
, width
15.2 mm
.
Hind
wing oval, length/width ratio 1.57; costal area wide, length/width ratio 2.80; nodal indentation at basal 0.33 wing length.
RP
+M1 length
2.8 mm
. Stem M short and oblique, bifurcating at basal 0.11 wing length. Branch M1 departing from stem M1+2 at same level of Sc+RA fork. Arculus (basal m-cua crossvein) convex, strong and oblique. Branch CuA arising basally from curved stem Cu (the CuA base is a weak concave oblique brace), curved anteriorly at contact with M3+4. Membrane infuscate with white basal-distal oriented band in the center. The band arising from wing base, terminating in distal 0.75 wing length, approximately 0.35 of wing width. Marginal membrane very thin.
Etymology.
The specific epithet is from the Latin
trinervus
, in reference to the unique 3-branched vein M in the hind wing.
Material.
Holotype
:
NIGP
142082 and
NIGP
142082a, part and counterpart. Body poorly preserved (vertical to the bedding plane). Two forelegs and right middle leg partly preserved. Four wings clear: left hind wing partly overlapped by left fore wing; right fore wing a little covered by the right hind wing.
Paratype
:
NIGP
142083 and
NIGP
142083a, part and counterpart of the hind wing. Almost complete with anal area just a little destroyed. Both specimens are deposited in the Nanjing Institute of Geology and Palaeontology (
NIGP
), Chinese Academy of Sciences.
Age and occurrence.
Middle Jurassic; Daohugou Village, Ningcheng County, Chifeng City, Inner
Mongolia
,
China
.
Remarks.
The similar colour bands are also present in the rock outside the fossil, so the yellow colour in the
holotype
is not the pattern of the wing and was formed during the diagenetic process.
FIGURE 1.
Sinopalaeocossus trinervus
sp. nov.
; a, holotype, NIGP142082, part; b, holotype, NIGP142082a, counterpart of NIGP142082; c, paratype, NIGP142083, part; d, paratype, NIGP142083a, counterpart of NIGP142083. All specimens are from the Middle Jurassic of Daohugou, Inner Mongolia, China. Scale bars represent 10 mm.
FIGURE 2.
Reconstruction of
Sinopalaeocossus trinervus
sp. nov.
from the holotype, NIGP142082.
FIGURE 3.
Reconstruction of the fore wing from the holotype, NIGP142082.
The
paratype
is the same as the
holotype
in respect to venation pattern. Although it is 1.4 times larger than the
holotype
, the size difference is not beyond the intraspecific variation demonstrated by some singing cicadas within Cicadomorpha (
Moulds, 2003
). Therefore, it is most conservative here to place two specimens in the same species.
The new species differs from the
type
in the hind wing with distinct colour pattern, while the latter has some granules in the wing membrane between RA2 and
RP
. Because of poor preservation of the
type
specimen, further comparison must await re-examination of the
type
specimen and the discovery of better-preserved material belonging to the
type
species.