FIRST HANGINGFLY (INSECTA: MECOPTERA: BITTACIDAE) FROM THE CRETACEOUS OF EUROPE, THE

Journal of Paleontology, Nov 2004 by Petrulevicius, Juli�n F, Jarzembowski, Ed A

INTRODUCTION

BITTACIDAE is small family of insects, but a major family of mecopterans, with about half of its genera known from the Mesozoic (Handlirsch, 1939; Sukatsheva, 1990; Novokschonov, 1993, 1997a, 1997b; Ren, 1993, 1997; Ansorge, 1996; Petrulevicius and Martins-Neto, 2001), mainly from the Jurassic. Cenozoic records are scarce and in most cases are assigned to extant genera (Jar/.embowski, 1980; Novokschonov, 1993; Pctrulevicius, 1998, 1999, 200 Ia, 200Ib).

Living bittacids are widespread in temperate and tropical climates. The wings are distinctly elongate and slender in their basal third. They are called hangingflies because they spend most of their time hanging by their forelegs or fore and middle legs (Byers, personal commun.) from low vegetation. They are predacious, catching with their hindlegs soft-bodied insects, such as true flies (Diptera) and spiders. Prey may be offered by males to females during courting, sometimes to more than one female. Hangingflies usually occur in mesic habitats, including stream margins, slowly flying short distances and sometimes sipping nectar from blossoms. Eggs are drought resistant and lay on the ground, where the larvae scavenge on dead insects (Jarzembowski, 1980; Byers, 1991).

GEOLOGY

Mecoptera are only found occasionally in the early Cretaceous of the United Kingdom (Jarzembowski, 1995). The described material was found by G. Bleach at the Clockhouse (Hanson) Brickworks (latitude 51 degrees 8 minutes N, longitude O degrees 19.5 minutes W), near Capel, Surrey, UK, in the Lower Weald clay Formation beneath the Clockhouse Sand (British Geological Survey sandstone bed 3) of late Hauterivian age (Rasnitsyn et al, 1998). The unique wing is a three-dimensional impression with brown-colored veins and pigmentation. The matrix is a well-cemented calcareous grey siltstone. Associated fossils include other disarticulated insect remains such as Diptera (true flies) and Odonata (dragonflies). The siltstone represents a scour fill in a predominantly mudstone sequence. The insect remains are thought to have been transposed by rivers during the wet season off a denuded, vegetated upland into a low-lying, muddy wetland with shallow open water; the paleoclimate is considered to have been subtropical/warm temperate (Jarzembowski and Mostovski, 2000).

SYSTEMATIC PALEONTOLOGY

In the present study, we use the wing venation nomenclature of Kukalov�-Peck (1983, 1991) and the phylogenetic classification of Bittacidae proposed by Novokschonov (1993). In Table 1 we give the equivalences with the venation wing nomenclature system of Comstock-Needham/Tillyard-Fraser (Comstock, 1918; Tillyard and Fraser, 1940).

MECOPTERA Packard, 1886

RAPTIPEDIA Willmann, 1987

BITTACIDAE Handlirsch, 1906

ANTIQUANABITTACUS new genus

Type species.-Antiquanabittacus nanus new species.

Diagnosis.-The main venational characters of the genus are as follows: 1) basal part of wing narrow; 2) RP3 4 MA RP3 4 distinctively curved; 3) MP4 CuAl 2 simple; 4) Kreuz der Bittaciden [rp3 4 ma-mpl 2, mpl 2-mp3 crossveins] not aligned (Z-shaped); 5) RA "spoon-like"; 6) posterior part of Kreuz reaching vein MP3 far from its base; 7) RP bifurcating more basally than MPl 2; 8) MP3 MP4 CuAl 2 short; 9) strong oblique crossvein present between ScP and RA; 10) crossvein present between distal part of AA3 4 and CuP; 11) RA simple; 12) crossvein present between RP1 2 and base of the "bowl" of the "spoon like" RA; 13) RP2 present.

Comparison.-Characters 1 and 2 are synapomorphies of Bittacidae sensu Novokschonov (1993). Characters 3-5 are synapomorphies of the new genus and Oroblttacus Villegas and Byers, 1981; Microbittacus Novokschonov, 1993; Mesobittacus Handlirsch, 1939; Preanabittacus Novokschonov, 1993; Anabittacus Kimmins, 1929; Baissobittacus Novokschonov, 1997a; Liaobiltacus Ren, 1993; and Jichoristella Ren, 1994. Character 6 is shared by the new genus with Preanabittacus, Liaobittacus, and Jichoristella and is considered a similarity. Characters 7 and 8 are possible synapomorphies of the new genus, Anabittacus, and Jichoristella. Characters 9 and 10 are possible synapomorphies of the new genus and Anabittacus. Character 11 is a symplesiomorphy of Anabittacus, Mesobittacus, Jichoristella, Anabittacus, and the new genus.

Character 12 seems to be a distal expression of a homologous vein present in most genera of Bittacidae, e.g., Assiobittacus Novokschonov, 1993; Sharabittacus Novokschonov, 1993; Probittacus Martynov, 1927; Sibirobittacus Sukatsheva, 1990; Megabittacus Ren, 1997; ICretobittacus Novokschonov, 1993; and Prohylobittacus Novokschonov, 1993. This vein is in a similar position in the genus Mesobiltacus.

Character 13 is a symplesiomorphy shared with Anabittacus, but not with Jichoristella, in which RP2 is absent (apomorphy).

Etymology.-From the Latin for "antiquity" and the recent genus Anabittacus.

Discussion.-The genera Orthobittacus Willmann, 1989 and Plessiobittacus Novokschonov, 1997b are readily distinguished by their supernumerary MP veins. The absence in the new genus of the apomorphic state RA3 4 sharply sagged excludes it from the fossil genera Assiobittacus, Sharabittacus, Probittacus, Sibirobittacus, Telobittacus Zhang, 1993, Megabittacus, Cretobittacus, Prohylobittacus, Palaeobittacus Carpenter, 1928, and all recent genera except Orobittacus and Anabittacus. MP4 CuA simple, Kreuz der Bittaciden not aligned (Z- or S-shaped), and "spoon-like" RA include Antiquanabittacus in a possibly monophyletic group formed by Orobittacus, Microbittacus, Mesobittacus, Preanabittacus, Anabittacus, Baissobittacus, Liaobittacus, and Jichoristella. Within this group, the presence of the posterior part of the Kreuz reaching MP3 far from its base is a similarity of the new genus with Preanabittacus, Liaobittacus, and Jichoristella. Anabittacus seems to belong to this group, but the presence of a faint c-scp crossvein and loss of the posterior part of the Kreuz, casts some doubt on this attribution. The latter character, however, is secondary because Anabittacus has a very specialized wing venation with many autapomorphies (Willmann, 1989, fig. 93).