Longioculus burmensis, N. gen., N. sp. (Orthoptera: Elcanidae) in burmese amber

2007·3.5 MB·

by  George Poinar

PROC. ENTOMOL. SOC. WASH.
109(3), 2007, pp. 649-655
LONGIOCULUS BURMENSIS, N. GEN., N. SP. (ORTHOPTERA:
ELCANIDAE) IN BURMESE AMBER
George Poinar, Jr., Andrej V. Gorochov, and Ron Buckley
(GP) Department of Zoology, Oregon State University, Corvallis, OR 97331,
U.S.A. (e-mail: [email protected]); (AG) Zoological Institute, Russian
Academy of Sciences, S. Petersburg 199034, Russia (e-mail: [email protected]); (RB)
9635 Sumpter Road, Florence, KY 41042-8355, U.S.A. (e-mail: [email protected])
—
Abstract. An adult orthopteran in Early Cretaceous Burmese amber is described
as a new genus and species, Longiociiliis burmensis Poinar, Gorochov, and Buckley. On
the basis ofits tegminal venation, three-segmented tarsi, and large spines on the hind
tibia, it is placed in the extinct family Elcanidae. This fossil differs from previously
described members ofthe family by its relatively small and slender body, protruding
eyes, enlarged scapes and antennal cavities, short pronotum, and unique venational
and leg armament characters.
Key Words: Orthoptera, Elcanidae, Longioculus, Longioculus burmensis, Burmese
amber, Early Cretaceous
Adult orthopterans in amber are rare, unpublished research 2002). Palyno-
since these insects are usually strong morphs from the amber beds where the
enough to free themselves from the resin. fossil originated have been assigned to the
A well-preserved Burmese amber orthop- Upper Albian of the Lower Cretaceous
teroid previously depicted in Poinar et al. (-100 mya) (Cruickshank and Ko 2003);
(2005) is the topic of this paper. The however, since the amber is secondarily
specimen has three-segmented tarsi, deposited, the age could be older.
a short pronotum, enlarged hind femora, The piece of amber containing the
and venational characters that align it specimen is rectangular in shape, mea-
mm mm
with members of the family Elcanidae suring 13 in length, 10 in width
mm
(Sharov 1968, Carpenter 1992, Gorochov and 6 in depth. The fossil is well
1995, Gorochov and Rasnitsyn 2002). preserved and complete except for the
tips of the antennae and wings, one side
Materials and Methods of the apex of the abdomen (including
Amber from Burma occurs in lignitic one cercus and the genital apparatus),
seams in sandstone-limestone deposits in the left metatibia and metatarsus and the
the Hukawng Valley, southwest ofMain- apical portion of the right metatibia.
gkhwan in the state of Kachin (26'20'N, Other fossils in the same amber piece are
96'36'E). Nuclear magnetic resonance three small adult beetles, one mite, one
(NMR) spectra of amber samples taken adult neinatoceran and several branched
from the same locality as the fossils plant hairs. Observations and photo-
indicated an araucarian (possibly Agathis) graphs were made with a Nikon SMZ-
source of the amber (Lambert and Wu, 10 stereoscopic microscope and Nikon
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Optiphot optical microscope (with mag- Cretaceous Cratoelcana Martins- Neto
nifications up to 650X). (Martins-Neto 1991), by the apices of the
branches of tegminal "C" positioned
Family Elcanidae Handlirsch, 1906 within a short distance of each other and
the most proximal crossvein in the area
Longioculus Poinar, Gorochov, and between R+ RS (possibly the basal part of
Buckley, new genus
— RS) situatednearthebasesofthethirdand
Description. Body relatively small fourth branchesofRA. From Cratoelcana,
and slender; scapes and antennal cavities with species over20 mm in length, thenew
greatly enlarged, occupying entire area genus differs in being much smaller (under
between compound eyes; compound eyes 8 mm in length).
large, protruding from head; ocelli lack- Type species. Longioculus burmensis,
ing; pronotum short, hind tibia with n. sp.
dorsal row ofdenticles and row ofmuch
larger spines in middle part (and possibly
Longioculus burmensis Poinar, Gorochov,
in distal part); ventral surface of hind
and Buckley, new species
basitarsus with row ofrather long spines;
(Figs. 1-12)
tegmina with both branches of false —
costa ("C") meeting within short dis- Description. Characters as listed un-
tance of each other on anterior wing der generic description. Alate male; body
margin; tegminal area between "C" and brown with transparent wing; length
Sc narrow; tegminal crossveins in visible body, 7.14 mm; length pronotum, 2.4
area between R+ RA reduced (most mm; length hind femur, 6.4 mm.
proximal crossvein in the area, possibly Head: Narrow; without rostral tuber-
basal part of RS, situated between bases cles between antennal cavities; ocelli not
of third and fourth branches of RA). observed; antennalcavities incontactwith
Etymology. ''Longioculus'" is from each other, with edges prominent; anten-
the Latin "oculus" for eye and "longus" nal scapes enlarged; antennal flagellum
for long, in reference to the protruding longerthan body(bothantennaecutoffat
eyes. The gen—der is masculine. edge of amber piece); filiform; antenno-
Diagnosis. On the basis of the nar- meres short, equal or subequal in size;
row, large spines on the hind tibiae, the each antennomere bears one to several
new genus may belong to the Late spines; genae narrow; clypeus and mouth-
Jurassic-Early Cretaceous subfamily Elca- parts more or less normal for Ensifera
ninae (= Baisselcaninae). Longioculus is (only lower edge oflabrum exposed).
similar in size to the Early Cretaceous Thorax: Pronotum saddle-shaped, with
genus Minelcana Gorochov, Jarzembow- anterior margin convex; pronotal dorsum
sky, and Coram (Gorochov et al. 2006) with seven circular light blotches with
and the smallest species of the Early dark borders located in depressions sym-
Cretaceous genus Panorpidium Westwood metrically positioned on each side; hind
(Westwood 1854), butcanbedistinguished part ofpronotum convex, not prolonged
from both these genera as well as from over abdomen; legs covered with short
othergeneraofElcanidae, exceptthe Early hairs; fore- and midfemora with pair of
Figs. 1-4. LongioculusburmensisinBurmeseamber. 1, Lateralviewofentirespecimen. Bar = 1.6 mm.
2, Metatarsusshowinglongspine(arrow) and twodenticles(arrowheads). Bar = 88 |im. 3, Dorsalviewof
anteriorportion showingprotrudingeyes (arrows) and roundcolored areas on pronotum. Bar = 542 \im.
4, Portion ofantenna showing scattered setae. Bar = 63 (im.
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Figs. 10-12. Longioculus bwinensis in Bunnese amber. 10, Venation of tegmina. Dotted portions
representreconstructed areas. Bar = 1 mm. 11, Frontalviewshowingprotrudingeyes, prominentantennal
cavities and enlarged antennal scapes. Bar = 1 mm. 12, Hind leg showing denticles and spines on dorsal
surface ofmetatibia and spines on ventral surface ofbasitarsus. Dotted portions represent reconstructed
areas. Bar = 1 mm.
rounded apical lobules, lacking denticles; dorsal surface bearing single row ofsmall
fore tibia with single apical outer spine; denticles from 25-31 jam in height and
mid- and hind tibiae with pair of apical 25-31 i^m in width at base; distance
spines; basal portion of hind tibia on between denticles 201-246 jam; denticles
Figs. 5-9. Longioculus burmensis in Burmese amber. 5, Frontal view. Bar = 375 )am. 6, Mouthparts.
Bar = 700 (im. 7, Metatarsus (arrow points to small spines on first tarsal segment of metatarsus) and
mesotarsus (arrowhead). Note rows of large spines opposite small spines on ventral surface of
basimetatarsus. Bar = 800 |J,m. 8, Denticles on proximal portion ofmetatibia. Bar = 575 jam. 9. Portion
ofabdomen showing remaining cercus. Bar = 800 ^m.
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654
replaced on middle part (and possibly on suggests that the entire distal portion
distal part) ofdorsal surface of hind tibia contained a row of large spines, which is
by large spines (only one complete spine, typical for elcanids. The depressed col-
265 |Lim long and 63 ^m wide, and one ored areas on the dorsum of the prono-
partial second spine visible); distance tum probably served as camouflage.
between first andsecondlargetibial spines,
315 jam; all tarsi with first segment longer Discussion
than 2nd and 3rd combined; apex of all
Fossils of the superfamily Elcanoidea
basitarsi with 2 pairs of apical spines; first appeared in the Early Permian and
midtarsus very short, less than Va as long extended into the mid-Cretaceous. Mem-
as basitarsus; third tarsal segments with
bers ofthe grasshopper-appearing family
well- developed, simple, slightly curved
Elcanidae first appeared in the Early
claws; arolium absent; fore- and midbasi-
Jurassic and representatives of the sub-
tarsi with 2 rows ofshort spines on dorsal family Elcaninae, which ranged from
and ventral surfaces; hind basitarsus with
Siberiato England and Brazil, wererather
two rows of spines, dorsal row composed common in Lower Cretaceous localities
of 27 short spines and ventral row with 7
(Martins-Neto 1991; Gorochov 1995;
large spines; midtarsus without spines;
Gorochov and Rasnitsyn 2002). The
tegmina membranous (wings folded); ve-
small size of Longioculus may indicate
nation as shown in Fig. 10; tegmina how it became entrapped in amber.
coloration light (transparent) with dark
veins and clear area between first and
Acknowledgments
second branches ofRA.
Abdomen: Short, robust; cercus slen- We thank Jim Davis for supplying the
der, pointed, approximately 1/3 length of amber, J. B. Lambert and Y. Wu, De-
abdomen; base of cercus with single, partment of Chemistry, Northwestern
small, outer sensilla; anal plate, subgeni- University, for their analysis of the
tal plate, and genital apparatus missing. amber, and RobertaPoinarforcomments
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Material examined. Holotype male on an earlier draft ofthis manuscript.
in Burmese amber from the Hukawng
Valley, southwest of Maingkhwan in the Literature Cited
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— Cruickshank. R. D. and K. Ko. 2002. Geology of
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Comments.—Unfortunately, the left Gorochov, A. V. 1995. System andevolution ofthe
hind tibia is missing and only the cseuebdoirndgesroEfnstihfeerZaoo(lOorgtihcoaplterIans)t.ituPtaer,tR1u.ssPiraon-
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VOLUME 109, NUMBER 3 655
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