Three new species of soldier beetles from Baltic amber (Coleoptera, Cantharidae)
Author
Fanti, Fabrizio
Author
Pankowski, Mary K.
text
Zootaxa
2018
2018-08-03
4455
3
513
524
journal article
29085
10.11646/zootaxa.4455.3.7
e805d477-ca64-4ea3-8990-285677f540b1
1175-5326
1457495
6B5ED1A9-FC34-4142-85AD-B35C73A427DE
Rhagonycha
(
Rhagonycha
)
maryae
FANTI & M. K. PANKOWSKI sp. nov.
(
Fig. 1
)
Description.
Adult, winged, slender and elongated. Female, defined on the basis of the large last sternite as wide as last tergite and apically sinuous and concave in the middle. Body length:
3.7 mm
; elytra:
3.1 mm
; antennae: approximately
2.8 mm
. Entirely dark brown including legs and antennae. Head almost completely exposed, rounded, with thin and shallow punctation. Eyes rounded, convex, inserted laterally to the head, inter-ocular dorsal distance about 2.4 times greater than eye diameter. Mandibles not visible. Maxillary palps 4-segmented, unequal in length, with the last palpomere securiform. Labial palps 3-segmented, last segment securiform. Antennae filiform, 11-segmented and with all segments pubescent, relative short, surpassing half of elytra; antennomere I (scape) robust, elongated, club–shaped; antennomere II robust, short, 1.7 times shorter than scape; antennomeres III–V elongated, robust (particularly the third), slightly shorter than first article; antennomeres VI–IX filiform, subequal, thinner and around 0.1–0.2 times shorter than previous three articles; antennomere X filiform, approximately 0.3 times shorter than previous one; antennomere XI filiform as long as antennomeres VI–IX. Pronotum larger basally, trapezoidal, larger than head, posterior corners rounded, posterior margin strongly bordered, anterior margin and sides slightly bordered, sides concave at half length, surface irregular and equipped with short, thick pubescence. Scutellum subquadrate with apex truncate and straight. Elytra slender, parallel-sided, very elongated and completely covering and slightly surpassing the last abdominal segments, wider than pronotum, apex rounded, surface rugose and equipped with many short setae. Posterior wings present, almost completely covered by elytra. Metasternum dark brown, rounded posteriorly, equipped with setae; sternites short, transverse, wrinkled; last sternite wide, rounded and sinuous at apex with central concavity. Legs short and pubescent; coxae massive; trochanters rounded; femora slightly enlarged; tibiae thin, cylindrical, longer than femora. All tarsi 5-segmented; first segment elongated; second tarsomere elongated and longer than first tarsomere; third about 2.3 times shorter than second, straight at apex; fourth tarsomere bilobed at sides; fifth flat and elongated; claws apparently bifid at apex without denticles at base.
Etymology.
Species named after Mary L. Pankowski, paternal grandmother of the second author, who provides immense love to her family, supports her community in numerous ways and inspires all with her indomitable spirit of optimism.
Holotype
.
Female, adult specimen included in Baltic amber, accession No.
USNM
PAL
712534 in
the
USNM
.
Type
locality.
Yantarny
settlement (formerly
Palmnicken
),
Sambian
(
Samland
)
Peninsula
,
Kaliningrad
Region,
Russia
.
Type
strata.
Baltic amber, Upper Eocene, Prussian Formation (Priabonian). Estimated age: 37.8–33.9 Mya.
Syninclusions.
Wood remains.
FIGURE 1.
Rhagonycha maryae
sp. nov.
in Baltic amber. A: Holotype, dorsal view, scale bar = 1.0 mm. B: Holotype, detail of head, pronotum and left antenna, scale bar = 0.5 mm. C: Holotype, ventral view, scale bar = 0.5 mm. D: Holotype, detail of leg and claws, scale bar = 0.2 mm.
Differential diagnosis.
The new species belongs to the genus
Rhagonycha
Eschscholtz, 1830
based on its bifid claws and for its anteriorly narrowed pronotum. Two species of the genus
Rhagonycha
have previously been described from inclusions in Baltic amber:
R. kryshtofovichi
(
Yablokov-Khnzorian, 1960
)
and
R. sucinobaltica
(
Poinar & Fanti, 2016
)
.
Rhagonycha kryshtofovichi
initially attributed to the genus
Malchinus
Kiesenwetter, 1863
was then transferred to
Rhagonycha
by
Kazantsev (2013)
based on the anteriorly narrowed pronotum, the fourth palpomere securiform and unmodified
terminalia
. In the genus
Rhagonycha
males and females possess the same pronotal shape. Thus, because the pronotal shape of
R. maryae
sp. nov.
is different from
R. kryshtofovichi
and
R. sucinobaltica
, it can be distinguished as a new species. (It’s worth noting here that the specimen of
R. maryae
sp. nov.
is a female because its last sternite is as wide as its last tergite, and it has an apical margin sinuous and concave in the middle. In the males of
Rhagonycha
, the last tergite is triangular and narrower than the last tergite.)
R. kryshtofovichi
is easily distinguishable from
R. maryae
sp. nov.
based on its larger size (with a body length of
7 mm
compared to
3.7 mm
for
R. maryae
), different pronotum and different length of the antennomeres (Yablokov-
Khnzorian 1960
). While the other known species
R. sucinobaltica
Poinar & Fanti, 2016
has similar dimensions (a body length of
3.5 mm
), it possesses a different pronotum that is more curved at the sides and less bordered at the posterior margin (
Poinar & Fanti 2016
).
Rhagonycha maryae
sp. nov.
also differs from other inclusions in Baltic amber known at a generic level as well as specimens known from mold impression and compression fossils in various rocky sediments (
Fanti 2017a
).
Remarks.
The amber piece measures
19x19
x
4 mm
and weighs
0.8 grams
. It has a round shape and is rather flat.