† Camelosphecia gen. nov., lost ant-wasp intermediates from the mid-Cretaceous (Hymenoptera, Formicoidea)
Author
Boudinot, Brendon E.
https://orcid.org/0000-0002-4588-0430
Department of Entomology & Nematology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA & Friedrich-Schiller-Universitaet Jena, Institut fuer Zoologie und Evolutionsforschung, 1 Erberstrasse, 07743 Jena, Thueringen, Germany
boudinotb@gmail.com
Author
Perrichot, Vincent
https://orcid.org/0000-0002-7973-0430
Univ. Rennes, CNRS, Geosciences - UMR 6118, F- 35000, Rennes, France
Author
Chaul, Julio C. M.
Pos-Graduacao em Ecologia, Departamento de Biologia Geral, Universidade Federal do Vicosa, 36570 - 900, Vicosa, MG, Brazil
text
ZooKeys
2020
2020-12-18
1005
21
55
http://dx.doi.org/10.3897/zookeys.1005.57629
journal article
http://dx.doi.org/10.3897/zookeys.1005.57629
1313-2970-1005-21
B99544631D5746C3AB90751157C9D0B5
610C6AAD64DF5166BE70E5751EC47FD6
†
Camelosphecia venator
sp. nov.
Fig. 16
Holotype.
Myanmar, Kachin State: Hukawng Valley [
NIGP163574
, deposited in
NIGP].
Figure 16.
†
Camelosphecia venator
sp. nov. holotype (NIGP163574)
A, D
right and left profile view of body, respectively
B, C
right and left profile view of head, respectively
E
left mesosoma zooming. Abbreviations:
ce
, compound eye;
cl
, clypeus;
md
, mandible;
mm
, masticatory margins;
oc
, ocelli;
occ
, occipital carina;
A2-A3
; abdominal segments 2 and 3;
mscx
, mesocoxa;
mspl
, mesopleural area of mesopectus;
mssctm
, mesoscutum;
mtcx
, metacoxa;
mtpl
, metapleural area of mesopectus;
oms
, oblique mesopleural sulcus;
pr
, prora;
prcx
, procoxa;
prnt
, pronotum;
prop
, propodeum. Note that indication of clypeus in
C
is exactly at its margin as seen in profile, which is concave, and should not be confused with convex right compound eye margin, also indicated. Clypeal concave shape is better evidenced in figure
B
. Also in
C
, mm indicated is from the right mandible, while mandible indicated is that of the left side. Scale bars:1 mm (
A, D
); 0.2 mm (
B, C, E
).
Diagnosis.
Identifiable as
Formicoidea
based on the definition given for the superfamily above. Associated with †
Camelosphecia
females by the multidentate mandibles, the shape of the clypeus, and the markedly prefurcal 1cu-a. †
Camelosphecia venator
differs substantially from †
C. fossor
and is undoubtedly a new species based on the following features: (1) "marginal cell" very short, area approximately equal to that of pterostigma; (2) 1m-cu
"postfurcal"
, or joining Mf distal to split of Rs+M; (3) 2r-rs joining Rsf proximal to 2r-rs; (4) "discal cell" wider; (5) "subdiscal cell" (enclosed by Cu, A, and 1cu-a) shorter; (6) petiolar node very well-defined, hump-like; and (7) prora (anteroventral keel of abdominal sternum III) shelf-like, strongly projecting. The male-based species differs from †
C. fossor
and †
C. cf. fossor
(BALBuTJ_38) by additional features which are expected due to sexual dimorphism, including having a distinct eye shape, shorter pronotum, twig-like profemora, and lack of the psammochaetae.
Measurements.
Male.
CL 0.98; VBL 0.21; HL 1.34; EL 0.58; LW 0.16; A1L 0.20; A2L 0.09; A3L 0.39; PnL 0.48; PnLm 0.68; WL 1.76; WLa 1.62; PtL 0.42. (
Note
: due to preservation and orientation, could not measure HW, CW, MW, PnW, MtW, MtL, MsW, and MsL.)
Description.
Male.
Head.
Cranium
"male-like"
for
Formicoidea
, particularly stem
Formicidae
and taxa of the poneriine clade (i.e., the
"poneroids"
of
Bolton 2003
): Cranium more-or-less hypognathous despite elongate postgenal bridge; compound eyes bulging, medially emarginate; vertex (bearing ocelli) produced dorsally. Features differing from expectation: Mandibles distinctly multidentate, with eleven teeth as determined from the holotype; masticatory mandibular margin elongate; mandibles bowed, as observed in the female; cranial mandibular condyle small; clypeus reduced, concave, reminiscent of male
Ponerini
; compound eyes
"binocular"
in that anterior medialmost ommatidia with direct line of sight across the clypeus; antennal toruli close-set and dorsally directed (distinct from female); ocelli hypertrophied (suggesting nocturnal flight); occipital carina incomplete, possibly encircling occipital foramen but definitely not extending to mandibular base. Antenna 13-merous. Scape short, ca. 3-4
x
as long as broad. Main body of pedicel approximately as broad as long. Flagellum elongate, each flagellomere several times longer than broad.
Mesosoma.
Pronotum short but muscular, with distinct bulge in profile view between
"neck"
and posterior
"collar"
; lateral face of mesopleuron broadly and deeply concave; concavity oriented dorsoventrally, apparently for reception of leg when fore leg completely retracted up to body; pronotum posterodorsally produced as lobe, lobe contacting fore wing tegulum; pronotum not forming ring posterior to fore coxae. Mesoscutum with deep and convergent notauli. Oblique mesopleural sulcus of mesopectus extending completely from anterior (
"epicnemial"
) margin to posterior (
"mesepimeral"
) margin. Mesothorax distinct laterally. Propodeum with dorsal and posterior faces curving into one another in profile view, apparently without distinct angular marking; posterolateral portion of propodeum, i.e., the area corresponding to the propodeal lobe, produced posteriorly, but not apparently in subrectangular form. Propodeal spiracle apparently situated high and anterior on segment, subtending metapleuron.
Legs.
Legs, overall, thin and without notable setal armament. Long setae not discernible. Protibial calcar apparently bifurcate apically. Mesotibia apparently with two ventroapical spurs, the anterior of which is thick compared to a seta and is barbirulate (
sensu
Bolton 2003
). Metatibial spurs and tarsi not preserved in holotype.
Metasoma.
Abdominal segment II with distinct petiolar node which is strong and convex; anterolateral corners carinate; form of subpetiolar process uncertain. Helcium (articulatory portion of abdominal segment II) well-defined, axial (situated at approximately segment midheight), and broad dorsoventrally and lateromedially. Prora (keel of abdominal sternum II) robust and triangular in profile view.
Wing venation.
Veins tubular as in female †
Camelosphecia
. Differing as follows: 1Rsf situated ca. 2
x
its length from pterostigma, nearly perpendicular to proximodistal length of wing; juncture of 1Rsf and Mf1 more distinctly angular; 1m-cu
"postfurcal"
, i.e., joining M distal to split of Rs+M; 2r-rs somewhat more proximal; "marginal cell" small, curve of posterior margin (as defined by Rsf) parallel to pterostigma; 2rs-m
"prefurcal"
, with anterior juncture proximal to 2r-rs; tubular portion of Mf distal to 2r-rs very short; "discal cell" pentagonal and less than 1.5
x
as long proximodistally as broad anteroposteriorly; 1cu-a joining M+Cu ca. 1
x
of its lengths proximal to split of Rs+M.
Preservation.
Amber matrix filled with uniformly distributed dark spheres. Metasoma from posterior portion of abdominal segment III, left meso- and meta-femora and distal segments, and right metatarsus removed due to specimen preparation. Hind wings not easily visible due to taphonomy. Specimen does not appear dehydrated or otherwise compressed or distorted.
Etymology.
The specific epithet suggests the likely predatory habits of the unknown female, while also highlighting the visual acuity of the male probably required for mate-seeking.
Comments.
We recognize that providing formal names to unassociated males risks inflating species-based biodiversity measures and runaway "parallel taxonomy" between sexes, as seen in various
Dorylinae
(e.g.,
Neivamyrmex
) and
Leptanillinae
(e.g.,
Leptanilla
). However, we are confident of the male-female pairing here due to the uniquely diagnostic mandibular conformation and markedly prefurcal 1cu-a crossvein. Moreover, the distinct wing venation and petiolar node of †
Cs. venator
provides both strong evidence of non-conspecificity with †
Cs. fossor
, and ample detail to associate unidentified females. For these reasons, we strongly recommend that any female which has a similar venational pattern and especially a nodiform petiole be considered conspecific with †
Cs. venator
, at least until further evidence accrues.
The marked reduction of the
male's
cranium and pronotum coupled with hypertrophied or bulging eyes compared to the female strongly suggests specialized and sex-specific life histories. Among extant
Formicidae
, similarly enlarged eyes are often associated with nocturnal flights. At light sheets, such bug-eyed males are often observed
en masse
, without presence of conspecific females, suggesting either limited flights by females or the female-calling syndrome. Unfortunately, the genitalia of the unique specimen were lost during specimen preparation, thus the presence of copulatory specializations remains unknown. However, it is apparent from other male
Formicoidea
from Burmite and other ambers that a wide array of sexual modifications are known.