Venation pattern and revision of Orthoptera sensu nov. and sister groups. Phylogeny of Palaeozoic and Mesozoic Orthoptera sensu nov.
Author
Béthoux, Olivier
Author
Nel, André
text
Zootaxa
2002
96
1
88
journal article
10.5281/zenodo.156112
f86b2225-fd69-4d14-888f-1656863a3244
11755326
156112
Gerarus bruesi
Meunier, 1909
(
Figs 1314
)
1909
Archaeacridites
bruesi
Meunier, 4546, fig. 2 (original description) 1919
Sthenaropoda bruesi
Handlirsch, 547, fig. 48.
1929
Archaeacridites
bruesi
ñ Vignon, 112, pl. 3, fig. 2.
1983
Gerarus bruesi
Burnham, 3536, figs 1819.
1992
Gerarus bruesi
KukalováPeck & Brauckmann, 2461, fig. 27. 1992
Gerarus bruesi
Carpenter 122, fig. 72.3a.
Material:
holotype
specimen MNHNLPR.51164, Laboratoire de Paléontologie, Muséum National d’Histoire Naturelle, Paris,
France
.
Geological settings: Stephanian, Upper Carboniferous, Commentry, Allier,
France
.
Diagnosis. CuPb lost in network below CuPa/CuPa. MA2 simple or very distally ramified; origin of MP in very distal position, just distal of first ramification of CuA + CuPa; CuPb very ramified.
Note. The revision of this specimen was necessary because
Burnham (1983: fig. 18)
did not figure vein ScA and because the convexity of main veins was unknown, partly indicated in
KukalováPeck & Brauckmann (1992)
, but with some differences with the present redescription. These last authors figured several veins at the wing base, which they named ‘MA’, ‘CuA’ and ‘AA1’. These veins are not visible on the fossil, particularly because there is a common basal stem of R + M + CuA.
FIGURE 13
.
Gerarus bruesi
, holotype specimen MNHNLPR.51164 (counterpart): reconstruction
and photograph (lightmirrored). (scale bar represents
5 mm
).
Redescription. Counterpart of a nearly complete forewing perfectly preserved with only the apex missing. Preserved length 46.0 mm, width
15.1 mm
; ScA reaching anterior margin
12.3 mm
from wing base; ScP anteriorly pectinate, with branches simple and slightly sigmoidal; base of
RP
18.5 mm
distal of wing base; ScP and R (+ M + CuA) basally separated; presence of a common stem R + (M + CuA); RA convex, anteriorly pectinate, with its branches dichotomously ramified; first branch of RA
8.7 mm
distal of base of
RP
; area between RA and
RP
with sigmoidal crossveins; convexity of
RP
neutral;
RP
dichotomously ramified distally, with one anterior branch fused with posterior branch of RA; CuA separated from M in the basal third of the wing; M dichotomously ramified into MA and MP; first anterior branch of MA close to
RP
, dichotomously ramified; area between branches of
RP
and branches of M with more or less regularly spaced straight crossveins; free part of CuA short, basal of its fusion with CuPa; CuA + CuPa posteriorly pectinate, with its two first posterior branches concave; sigmoidal crossveins between M and CuA + CuPa; CuPa short basal of its fusion with CuA; CuPa with an apical fork; a network of irregular cells in area between CuA + CuPa and CuPa; division of CuP into CuPa and CuPb near wing base; an anterior branch of CuPb (CuPb), lost in the network between CuPb and CuPa, posterior branch of CuP (CuPb) divided into three long branches; area between CuPa/CuPa and CuPb very broad (largest width opposite origin of CuPa /CuPa), with an irregular network of cells; 1A apparently separated from CuP close to the base of the wing, distally ramified; three main veins in anal area basal of 1A, only the third being branched.
Comparison with other
Geraridae
.
Gerarus bruesi
is very similar to
Gerarus danielsi
. These two taxa share: (1) a simple MA2 or very distally ramified; (2) an anterior branch of MP simple or very distally ramified; (3) a network of cells in area between CuPa/CuPa; (4) a densely ramified CuPb.
Gerarus vetus
, as figured by
KukalováPeck & Brauckmann (1992: fig. 13)
, has different right and left forewings, with apparently different organisation of veins MA, MA1, MA2 and MP. Nevertheless, the right forewing has an anterior branch of MA very close to
RP
and these veins being connected by a short crossvein. This character is also present in
Gerarus bruesi
.