Review of Mesozoic Perissommatidae (Insecta: Diptera)
Author
Lukashevich, Elena D.
Author
Blagoderov, Vladimir A.
text
Zootaxa
2020
2020-01-08
4718
4
481
496
journal article
24411
10.11646/zootaxa.4718.4.3
c3fec010-6e0c-41e3-aece-3c6caccc951a
1175-5326
3602674
32C51811-97BA-40E4-B503-F25F8C4CF98A
Palaeoperissomma
Kovalev in
Kalugina & Kovalev, 1985
(
Figures 7A, B
,
8
A–D)
Palaeoperissomma
:
Kalugina & Kovalev 1985: 115
.
Palaeoperissomma
Kovalev in
Kalugina & Kovalev, 1985
:
Lukashevich 2011: 32
.
Type species
.
Palaeoperissomma collessi
Kovalev in
Kalugina & Kovalev, 1985
(Kubekovo, Siberia, J
2
).
Species included.
Besides
type
species,?
Palaeoperissomma demetrii
Kovalev, 1990
(Turga, Transbaikalia, K
1
) and
P. ornatum
Lukashevich, 2011
(Shar Teg,
Mongolia
, J
3
).
FIGURE 7.
Mesozoic
Perissommatinae
(modified originals of V.G. Kovalev). A–B.?
Palaeoperissomma demetrii
Kovalev, 1990
, holotype PIN No. 1742/667 (Turga, K
1
). A. Total view. B. Antenna. C. Total view of
Gurvaniella hosbayari
Kovalev, 1986
, holotype PIN No. 3149/1789 (Gurvan, K
1
). Scale bars 1 mm. Figs A, B after
Kovalev 1990
: fig. 105a, b; Fig C after
Kovalev 1986
: fig. 97a.
FIGURE 8.
Mesozoic
Perissommatinae
. A, B. Head and total view of
Palaeoperissomma collessi
Kovalev in
Kalugina & Kovalev, 1985
, PIN No. 1255/1341 (Kubekovo, J
2
). C, D. Head and total view of?
Palaeoperissomma demetrii
Kovalev, 1990
, holotype PIN No. 1742/667 (Turga, K
1
). E, F. Head and total view of
Gurvaniella hosbayari
Kovalev, 1986
, holotype PIN No. 3149/1789 (Gurvan, K
1
). Scale bars 200 μm (A, C, E), 1 mm (B, D, F). Abbreviations:
e
, eye;
f
, vein-like fold;
o
, ocelli.
Remarks.
Two of three known species were described based on the single isolated wings each (
Kalugina & Kovalev 1985
;
Lukashevich 2011
):
P. collessi
(
holotype
PIN, No.1255/261) and
P. ornatum
(
holotype
PIN, No.4270/2278). An additional specimen of type species (PIN, No.1255/1341) was collected from the same locality (Kubekovo) in 1989 and studied herein (
Fig. 8A, B
). Some characters of living
Perissomma
are observed in body structures: V-shaped suture of the tipuloid type; thorax with large metanotum; legs slender, rather elongate, without tibial spurs. Probably three ocelli placed close together in a triangle on the dorsum of the head are present too. As in
Perissomma
, antenna moniliform, rather short and stout, with 11 segments, segments 2 and 3 enlarged (pedicel and first flagellomere), segment 11 very small, all segments with fine setae only. However, all segments are transverse (shorter than broad).
The
holotype
of?
P. demetrii
(PIN, No. 1742/667) was re-studied by us (
Figs 7A, B
;
8C, D
).
Kovalev (1990)
tentatively suggested that it was a male, but re-examination revealed elongated cerci, therefore the specimen is a female. Visible facets are of similar size. In the original description Kovalev noted that the pattern of antenna (11 segments, enlarged pedicel and tiny last flagellomere) and U-shaped suture on mesonotum (
Fig. 7 A,B
) are similar to living
Perissomma
, however, the robust habitus differs from one of
Perissomma
and from habitus of Jurassic
P. collessi
as now became obvious. Due to poor state of wing preservation Kovalev was hesitant in the generic attribution of this species and these doubts remain (see Discussion).