Snakefly diversity in Early Cretaceous amber from Spain (Neuropterida, Raphidioptera)
Author
Fuente, Ricardo Perez-de la
Author
Penalver, Enrique
Author
Delclos, Xavier
Author
Engel, Michael S.
text
ZooKeys
2012
204
1
40
http://dx.doi.org/10.3897/zookeys.204.2740
journal article
http://dx.doi.org/10.3897/zookeys.204.2740
1313-2970-204-1
Baissoptera? cretaceoelectra
Perez-de
la Fuente,
Penalver
,
Delclos
& Engel
sp. n.
Figs 2, 3
Holotype.
MCNA 12068.4, from
Penacerrada
I amber; fore- and hind wing distal fragments. Three associated hymenopterans are preserved as syninclusions.
Diagnosis.
Fore- and hind wing with a relatively long pterostigma with a strongly oblique and slightly sinusoid pterostigmal crossvein placed beyond pterostigmal midlength; fore- and hind wing with one closed radial cell distal to pterostigma; forewing Rs with six branches; forewing with at least eight closed subradial cells.
Description.
Sex unknown. Veins with some strong, very short setae preserved, membrane hyaline. Forewing.Length of preserved fragment 6.4,maximum width 2.8;wing apex relatively rounded; pterostigma relatively long (2.4 long, length ca. eight
times
basal pterostigmal width), slightly widening distally, not conspicuously infumate as preserved; pterostigma with a strongly oblique and slightly sinusoid pterostigmal crossvein placed beyond pterostigmal midlength, basally closed by a crossvein; pterostigma longer than any radial cell; R with two branches beyond pterostigma;at least three radial cells present, one closed radial cell partly distal to pterostigma; Rs with six branches and at least eight closed subradial cells;MA at least with two branches; gradate seriesveryregular, almost following a staircase-like pattern. Hind wing.Length of preserved fragment 5.9,maximum width as preserved 2.7;wing apex more pointed than in forewing;costal field distinctly narrower than in forewing; one c-sc crossvein preserved;pterostigma relatively long (2.5 long, length ca. 10 times basal pterostigmal width), slightly widening distally, not conspicuously infumate as preserved, starting 0.5 (twice pterostigmal basal width) beyond termination of Sc; pterostigma with a strongly oblique and slightly sinusoid pterostigmal crossvein placed beyond pterostigmal midlength, basally closed by a crossvein;pterostigma longer than any radial cell;R with two branches beyond pterostigma;at least five radial cells present, one small closed radial cell distal to pterostigma;Rs with five branches and at least seven closed subradial cells; MA at least with two branches; gradate seriesveryregular, almost following a staircase-like pattern.
Figure 2.
Baissoptera? cretaceoelectra
sp. n., holotype MCNA 12068.4. A forewing B hind wing. Scale bars = 1 mm.
Figure 3. Drawings of
Baissoptera? cretaceoelectra
sp. n., holotype MCNA 12068.4. A, forewing B hind wing. Scale bar = 1 mm (both wings at the same scale).
Etymology.
The specific epithet is a combination of the Greek words cretaceus (taken from the period name, although specifically meaning
"chalky"
) and elektron, meaning
"amber"
.
Comments.
Within the current taxonomic framework, the numerous crossveins of MCNA 12068.4 are indicative of placement in the
Baissopteridae
. Unfortunately, neither base of the wing is preserved, thus important characters such as the maximum width of the costal field, the pattern of distribution of c-sc crossveins (= costal crossveins), the separation between M and CuA in the forewing, and the shape of the basal piece of MA, are unknown. Also, the infumation of the pterostigma is not evident in the holotype, but it is uncertain if this could have been caused by taphonomical processes and is, therefore, not used as a diagnostic character although if the absence of infumation is true of the species in life, then it would represent a remarkable difference from all other described baissopterids. Fortunately, the pterostigma can be delimited thanks to the relative parallelness of C and R (R tends to conspicuously change its slope beyond the pterostigma in the other baissopterids) and also the greater thickness of both veins.
The specimen is tentatively classified within the genus
Baissoptera
as it has the pterostigmal crossvein most similar to the diversity found within this genus. Today just two of the 12 species currently classified within the genus
Baissoptera
, i.e.,
Baissoptera brasiliensis
Oswald, 1990 and
Baissoptera lisae
Jepson, Ansorge & Jarzembowski, 2011, lack a pterostigmal crossvein in both fore- and hind wings (
Oswald 1990
: p. 156, figs 3, 4;
Jepson et al. 2011
: p. 393, text-figs 6A, B). Some genera can even show an additional, straight pterostigmal crossvein in a more basal position at least in the hind wing, i.e.,
Baissoptera kolosnitsynae
Martynova, 1961 and
Baissoptera pulchra
(Martins-Neto and Nel, 1992) (
Martynova 1961
: p. 81, fig. 7;
Martins-Neto and Nel 1992
: p. 428, figs 2, 3). Regarding the other taxa currently classified within the
Baissopteridae
, the genera
Lugala
and
Cretoraphidia
lack a pterostigmal crossvein, at
least
in the hind wing (
Ponomarenko 1988
: p. 75, fig. 4; 1993: p. 70, figs 7, 9, 10); whereas the genera
Cretoraphidiopsis
and
Austroraphidia
, althoughshowing a pterostigmal crossvein situated beyond pterostigmal midlength, have it not as strongly oblique as in
Baissoptera? cretaceoelectra
sp. n., both showing irregular gradate series in both wings and a much lesser number of Rs branches in the forewing (three in
Austroraphidia
, four in
Cretoraphidiopsis
).
Cretinocellia cellulosa
Ponomarenko, 1988 has been recently transferred from the
Baissopteridae
to the
Mesoraphidiidae
by
Bechly and Wolf-Schwenninger (2011)
based on its lack of pterostigmal crossvein(s) and a Sc ending about midwing length. Although these two characters are also present in
Cretoraphidia certa
Ponomarenko, 1993 and
Cretoraphidia magna
Ponomarenko, 1993 (
Ponomarenko 1993
: p. 70, figs 7, 10), in both, the crossvenation is relatively higher than in
Cretoraphidia cellulosa
and should therefore remain in
Baissopteridae
for the moment. Consequently,
Bechly and Wolf-Schwenninger (2011)
also noted that the genus
Cretinocellia
might occupy a basalmost position within
Mesoraphidiidae
according to its relatively high crossvenation compared to the other mesoraphidiids. On the other
hand
, we still consider
Arariperaphidia rochai
Martins-Neto and Vulcano, 1989 as incertae sedis rather than as a baissopterid (contra
Bechly and Wolf-Schwenninger 2011
), owing to its lack of preserved characters indicating a more conclusive assignment. The shape and location of the pterostigmal crossvein is quite diagnostic for
Baissoptera? cretaceoelectra
. Only
Baissoptera minima
Ponomarenko, 1993 shows such a strongly oblique pterostigmal crossvein within the family, even slightly sinusoid as in the new species, in a relatively elongate pterostigma (length ca. eight times basal pterostigmal width) (
Ponomarenko 1993
: p. 64, fig. 2). However, the pterostigmal crossvein is located before pterostigmal midlength and Rs is poorly branched in
Baissoptera minima
.
Baissoptera? cretaceoelectra
has Rs in the forewing with more branches currently described within the genus. The remaining
Baissoptera
species always show a lesser number of branches of Rs in the forewing, i.e., five (
Baissoptera brasiliensis
,
Baissoptera grandis
Ren in Ren et al. 1995,
Baissoptera liaoningensis
Ren, 1994,
Baissoptera lisae
, and
Baissoptera sibirica
Ponomarenko, 1993), four (
Baissoptera elongata
Ponomarenko, 1993,
Baissoptera euneura
Ren, 1997,
Baissoptera kolosnitsynae
, and
Baissoptera martinsoni
Martynova, 1961), or three Rs branches (
Baissoptera pulchra
and
Baissoptera minima
) (
Martynova 1961
;
Oswald 1990
;
Martins-Neto and Nel 1992
;
Ponomarenko 1993
;
Ren 1994
, 1997;
Ren et al. 1995
;
Jepson et al. 2011
). Although
Baissoptera cellulosa
Ponomarenko, 1993 (based on a forewing lacking the apex) could also possess six branches of Rs and does have a sinuate pterostigmal crossvein presumably beyond pterostigmal midlength (
Ponomarenko 1993
: p. 65, fig. 3), it differs from
Baissoptera? cretaceoelectra
in that the pterostigmal crossvein is just slightly oblique and the more abundant crossvenation. The only other described baissopterid with such an elevated number of branches of Rs is
Cretoraphidia certa
, but it lacks a pterostigmal crossvein as has been discussed, and in addition Sc ends in a more basal position. Furthermore, the pterostigmal length of the new species is elongate when compared to the other lengths shown by the other species within the genus
Baissoptera
. Only
Baissoptera grandis
has a longer pterostigma, its length about 11 times its basal pterostigmal width (
Ren et al. 1995
: p. 175, fig. 2). The shortest pterostigmata within the genus are found in
Baissoptera martinsoni
and
Baissoptera elongata
, their lengths ca. four and six times their basal pterostigmal widths, respectively (
Martynova 1961
: p. 80, fig. 6;
Ponomarenko 1993
: p. 67, fig. 5). Naturally, our placement of this species in
Baissoptera
is a conservative position based on the lack of complete material. More completely-preserved specimens, in which the wing base characters noted above could be assessed, may force a reconsideration of the generic assignment.