New and little known taxa of the order Orthoptera (Insecta) from the Upper Triassic and Lower Jurassic of England
Author
GOROCHOV, ANDREI V.
Author
CORAM, ROBERT A.
text
Palaeoentomology
2023
2023-04-28
6
2
198
204
http://dx.doi.org/10.11646/palaeoentomology.6.2.11
journal article
10.11646/palaeoentomology.6.2.11
2624-2834
7928885
1E80FE4B-F846-4243-ABB9-15CF7F8341F4
Genus
Plesioschwinzia
Zessin, 1988
Type
species.
Plesioschwinzia thalassophila
Zessin, 1988
Remarks.
The genus was described from one aberrant tegmen having four more or less long and oblique branches of Sc, a primitive structure of MA (with 1MA1, 2MA1 and MA2 located as in
Locustopsis
and
Mesolocustopsis
), two branches of MP+CuA1 (as in
Locustopsis
and
Zeunerella
), and unusual venation in the area between MA and MP+CuA1. The latter area has a false branch arising from MA before the MA2 base and additionally connecting MA with the costal branch of MP+CuA1 (this is undoubtedly an individual aberration of venation, sometimes occurring in one or even both tegmina of some specimens of recent
Orthoptera
species). Thus, the presence of such a branch cannot be a generic or species diagnostic character. Differences of this genus from
Locustopsis
are mainly in the less numerous long oblique branches of tegminal Sc (1–4 instead 6–8); this character is not reliable, because intermediate variants are possible, and many specimens have an inadequately preserved costal area. This genus differs from
Schwinzia
in the presence of two (instead of three) branches of tegminal MP+CuA1 (possibly the Early Jurassic species
Locustopsis anatolica
Sharov, 1968
, also having three branches of tegminal MP+CuA1, could be tentatively included in the genus
Schwinzia
).
Plesioschwinzia
is distinguished from
Parapleurites
by its distinctly longer Sc, if the tegmen of its
type
species
P. gracilis
Brauer, Redtenbacher & Ganglbauer, 1889
was correctly pictured by the authors (
Brauer
et al
., 1889
: fig. II, 17).
This genus may contain several species originally placed in other genera, which had a long Sc with 1–4 rather long and oblique branches in its proximal and middle parts, a primitive MA and two branches of MP+CuA
1 in
the tegmina:
Gomphocerites bernstorffi
Geinitz, 1880
,
Locustopsis lacera
Zessin, 1983
,
L
.
procera
Zessin, 1983
,
L
.
pulchella
Zessin, 1983
, and
L
.
kruegeri
Zessin, 1983
from the Lower Jurassic of
Germany
;
L
.
lacoei
Cockerell, 1916
,
L
.
uvarovi
Zeuner, 1942
,
L
.
gracilis
Zeuner, 1942
, and
L
.
constricta
Zeuner, 1942
from the Lower Jurassic of
England
;
L
.
posterior
Gorochov, Jarzembowski & Coram, 2006
from the Lower Cretaceous of
England
. However, the last two species, as well as some of the others, may have been based on specimens in which only some of an originally greater number of Sc branches were visible, and so may not belong to
Plesioschwinzia
. However, the
type
species of this genus and the new species, described below, undoubtedly have only four such branches.