Abstract
A new insect species (dagger Bittacopsocus megacephalus Beutel, Prokop, Muller et Pohl gen. et sp. nov.) is described, based on a single small male (ca. 2.5 mm) embedded in mid Cretaceous Burmese amber. The species shows some resemblance with the mecopteran family Bittacidae, mainly due to strongly elongated and thin legs.
However, the structural affinities are apparently due to convergency. Different features, but especially the mouthparts and the pattern of wing venation, indicate that the species belongs to the extinct order t Permopsocida (?Archipsyllidae).
However, it differs markedly from all species previously described in this extinct group. The very thin and strongly elongated legs are probably autapomorphic.
A very unusual feature is the antenna with only seven segments and extremely elongated flagellomeres. The two pairs of wings are unusually narrow.
M and CuA are basally fused. Proximal rows of spines, two series of closed cells, and a distinctly increased number of terminal branches of M are present in the forewings, in contrast to other archipsyllid genera.
It is conceivable that Bittacopsocus megacephalus used its long legs to rest suspended in the vegetation like Bittacus. The head structures tentatively suggest predatory behavior but the feeding habits are unclarified yet.