Table Of ContentBull. nat. Hist. Mus. Lond. (Geol.)56(1): 43^5 Issued29June2000
Burmapsilocephala cockerelli, a new genus and
species of Asiloidea (Diptera) from Burmese
amber
GAIMARI
S.D.
Smithsonian Institution, Washington, D.C. 20560 USA
MOSTOVSKI
M.B.
ArthropodLabioratory, PaleontologicalInstitute, RussianAcademy ofSciences, Profsoyuznaya Str. 123,
Moscow 117647, Russia
SYNOPSIS. PsilocephalaelectrellaCockerellisfigured,andanotherasiloidfly,Burmapsilocephalacockerelligen.etsp.nov.,
isdescribedfromBurmeseamber.ThenewgenusishypothesizedtobeclosetotheextantgenusApsilocephala.Thephylogenetic
positionofApsilocephalaisdiscussed.
INTRODUCTION slightlylongeranddoesnotappeartobeasfleshyasinApsilocephala.
Postpronotallobehasasingle,strongseta.Mesonotumcoveredwith
hairs. One pair of strong scutellar setae present. The foretibial
Psilocephala electrella was described by Cockerell (1920) from macrosetaehavetheformula5v,5pv,5av,5pd,5ad.Thehindtibiahas
Burmese amber based on an inclusion with incomplete wings and
fewerthan lOpdmacrosetae.
body. Through the courtesy ofMrA.J. Ross (Natural History Mu-
seum, London) and Prof. A.P. Rasnitsyn (Paleontological Institute, Remarks. Burmapsilocephala is taxonomically close to the ex-
Moscow) the collection of flies in Burmese amber stored in the tant genus Apsilocephala Krober, 1914, with only minor
Natural History Museum, including the holotype of this species morphological differences. In Apsilocephala the pedicel is about
(In.20148)(Fig. 1),wasavailableforstudy.Itisdifficulttobecertain halfthelengthofthescapeorfirstflagellomere,whicharesubequal.
thatthisspeciesbelongstothegenusPsilocephala,becausecharacter- Theantennalstylusis 1.0to 1.5 timeslongerthanantennalsegments
istic features are not preserved. Another specimen (In.20167) (Fig. 1-3. The postpronotal lobe has long hairs but no macrosetae. Two
4)belongingtothesuperfamilyAsiloideawasdiscovered,withwing pairs ofscutellarsetae are usuallypresent, althoughonepaircanbe
venation and leg structures resembling those of the holotype of strongerthan the other. The foretibia ofApsilocephala has only 2-
Psilocephala electrella. However, itdiffersfromthelatterinhaving 3pdand0-lad,andhindtibiahasmorethan 1Opd.Burmapsilocephala
a slender body and more robust thoracic bristles, except for the differsfromApsilocephalaandtherevids,inpossessingalongstylus
dorsocentrals. On balance, itprovedto be arepresentative ofa new and vein R5 ends near the wing tip. Remarkable is the absence of
genus describedhere. robust dorsocentrals inBurmapsilocephala.
Burmapsilocephala cockerelli sp. nov. Figs 2-A
SYSTEMATIC DESCRIPTIONS
Name. The name is in the memory ofT.D.A. Cockerell.
Material and locality. Holotype In.20167, from Burmese
The following abbreviations are used:
amber,HukawngValley,Myanmar(Burma);probablyUpperCreta-
Forthoracicmacrosetae:ppn=postpronotal,npl=notopleural,sa
ceous (see Zherikhin and Ross, this volume).
= supraalar,pa = postalar.
For the positions of setal rows in tibiae: v = ventral, pv = Description. Female, the tip ofabdomen not discernible. Body
posteroventral,av=anteroventral,d=dorsal,pd=posterodorsal,ad and legs slender.
= anterodorsal. Head: Fronsnarrow,bare.Ocellartrianglenearlyflattened. Scape
(1), pedicel (2), and firstflagellomere (3) subequal inlength. Scape
and pedicel with short hairs apically. First flagellomere slightly
OrderDIPTERA tapered to apex. Stylus apical, 2.5 times longer than segments 1-3
SuperfamilyASILOIDEA combined.
FamilyAPSILOCEPHALIDAE Thorax (Fig. 2): Postpronotal lobe relatively large. Mesonotum
GenusBURMAPSILOCEPHALA nov. highly arched, covered with short hairs. Postalartubercles distinct.
Macrosetal pattern: Ippn, 2npl, \sa, \pa. Scutellum small, trapezi-
Name. The name is derived from Burma, and the genus name form; with 1 pair strong macrosetae; covered with long hairs.
Apsilocephala. Pteropleuron bare. Metathorax relatively large. Halter pale with
darkerknob. Fascicle oflong delicate hairs anteriorto halter.
Type species. Burmapsilocephala cockerelli nov.
Wing (Fig. 3) with cell m3 closed and stalked; costal vein termi-
Diagnosis. Scape, pedicel, and first flagellomere subequal in nates at wing tip.
length.Antennalstylus2.5 timeslongerthanantennalsegments 1-3 Legs: Coxae with long hairs. Hind femur without macrosetae.
combined, and slightly thinner than in Apsilocephala. Proboscis Foretibia with apical ringlet of five macrosetae, and rows of
©TheNaturalHistoryMuseum,2000
44 S.D. GAIMARI AND M.B. MOSTOVSKI
Fig.4 Burmapsilocephalacockerelligen. etsp. nov.,holotypeIn.20167,
Burmeseamber. Length5.3mm.
Fig. 1 PsilocephalaelectrellaCockerell,holotypeIn.20148, Burmese
amber.Widthofwing 1.5mm Tergite 2 longer than others; tergite 7 slightly shorter than others.
Tergites dark with pale, narrow band along lateral and posterior
macrosetaewithformula5v,5ad,5pd,5pv,5av.Midtibiawithapical margins.Tergites 1-5coveredsparselywithshorthairs;6-8covered
ringletof4-5 macrosetae, androws ofmacrosetaewithformula3d,
with short hairs. Tergite 9 smaller and slender than the others, with
4ad, 2p, 3pv, 2pd. Hindtibia with asymmetrical, apical ringlet of long and short seta-like hairs.
macrosetae, and rows ofstrong and weak macrosetae with formula
3ad, 1 (?8)pd, \pv (in distal third), 6av. Metatarsus with rows of Measurements. Bodylength(withoutantennae)=5.3mm,wing
strong hairs ventrally (at least in basal half), and with lateral setae, length = 2.7mm, wing width = 1.2mm.
and with 4 (?5) strong apical setae. Tarsal segments 2-5 haired and DISCUSSION. Apsilocephalawasoriginallydescribedasamember
with apical setae. Empodium bristle-like. Pulvilli and tarsal claws of the Therevidae (Krober, 1914), but this certainly represents an
small. enigmatic genus. Apsilocephala was considered separate from
Abdomen(Fig.4):Tergite 1 threetimesshorterthantergite2;with Therevidae byIrwin (1976) andIrwinandLyneborg (1981), butthe
lateral fascicles of long hairs. Tergites 3-6 subequal in length. positionofthegenuswasnotconsideredfurther.Apsilocephalawas
givenfamilystatus,andincludedthegeneraClesthentiaWhite, 1914
and ClesthentiellaNagatomi, Saigusa, NagatomietLyneborg, 1991
(Nagatomietal, 1991a).However,themonophylyofthegroup,orat
least its ranking at family-level, was questioned due to absence of
definitive synapomorphies (Sinclair etal, 1994). The phylogenetic
comments herein do not address the monophyly or internal classi-
fication ofthe familyApsilocephalidae, butonly its position within
the Diptera.
Nagatomi et al (1991a, c) hypothesized a close affinity of
Apsilocephalidae with the Middle to Late Jurassic family
Rhagionempididae based on superficial similarities, but noted that
the most important characteristics (e.g. male and female genitalia,
condition of empodium) are not known in the rhagionempidids.
Nevertheless, Nagatomi and Yang (1998) did synonymize
Apsilocephalidae under fossil Rhagionempididae. It seems to be
precociousnow.Further,Nagatomietal(1991a, b, c)andNagatomi
(1992, 1996) hypothesized a sister-group relationship with
Empidoidea or with Eremoneura, based again on the presence of
surstyli in the male genitalia. Griffiths (1994, 1996), Sinclair et al
(1994), Cummingetal(1995), andZatwarnicki (1996)rejectedthis
hypothesis based on the observation that the 'surstyli' of
Apsilocephalidae were erroneously considered homologous to the
structuresofEmpidoideaandEremoneura. Sinclairetal(1994) and
Figs2,3 Burmapsilocephalacockerelligen. etsp. nov.,holotype Cumming etal (1995) retained the genusApsilocephala within the
In.20167,Burmeseamber. 2,headandthorax; 3,wingvenation; scale concept ofTherevidae, but as incertae sedis (without further com-
bar 1mm. menton Clesthentia or Clesthentiella).Additional considerationby
NEW ASILOIDEA FROM BURMESE AMBER 45
Yeates (1994) also maintained this position ofApsilocephala very ACKNOWLEDGEMENTS. TheauthorswouldliketothankMrAJ.Rossfor
near to Therevidae, and current morphological (M.E. Irwin, pers. access to the collectionofDipterain BurmeseamberattheNatural History
comm.)andmolecular(L.L.YangandB.M.Wiegmann,pers.coram.) Museum, London, and Prof. A.R Rasnitsyn forencouraging this work, Drs
studies also suggest that Apsilocephala is very near or possibly N.L.Evenhuis,M.E. Irwin,andanonymousrefereeforreviewingthemanu-
within Therevidae. Therefore, the concept ofApsilocephala or the script,K.C.Holstonforcommentsonanearlierversion,andDrsD.K.Yeates
Apsilocephalidae as being near the stem of Eremoneura could be and B.M. Wiegmann for comments on the relationships ofApsilocephala.
rejectedinfavourofitsoriginalpositionwithinorneartheTherevidae. Many thankstoMrPeterYork(NHM)fortakingphotographs.
However, we keep the families Apsilocephalidae and Therevidae
apart and avoid the formal synonymy until the position of fossil
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