Oecophylla eckfeldiana Dlussky, 2008

Dlussky, Gennady M., Wappler, Torsten & Wedmann, Sonja, 2008, New middle Eocene formicid species from Germany and the evolution of weaver ants, Acta Palaeontologica Polonica 53 (4), pp. 615-626 : 619-621

Oecophylla eckfeldiana Dlussky sp. nov.

Fig. 4 .

Etymology: After the type locality.

Type material: Holotype: PE−2000/8 (♀). Paratypes: PE−1992/253 (♀), PE−1994/159 (♀), PE−2000/1948 (minor worker), PE−2000/1947 (head of major worker), PE−2000/1951 (♀). Other specimens (♀♀): PE−1994/160, PE−1994/162, PE−1994/186, PE−1997/26, PE−1998/3, PE−1998/5, PE−1998/8, PE−1998/14, PE−1998/16, PE−2000/9, PE−2000/11, PE−2000/12 (all NHMM).

Type locality: Eckfeld , Germany .

Type horizon: Middle Eocene, ca. 44 Ma ( Mertz et al. 2000).

Diagnosis.—Head of gynes of O. eckfeldiana is about as long as wide as in O. atavina (longer than wide in O. longiceps , and wider than long in fossil O. superba and both living species), but in O. atavina the head is distinctly narrower in front than behind, and the petiole is longer (twice as long as wide and high in O. atavina and a little longer than wide and high in O. eckfeldiana ).

Description.—Gyne. BL 10–14 mm, AL 3–4 mm, FWL 10–13 mm. Head about as long as wide, with convex sides, smoothly rounded occipital corners and feebly convex occipital margin. Anterior margin of clypeus rounded. Eyes comparatively small, oval, situated on the midlength of head; maximum eye diameter about 0.3–0.4 times head length. Mandibles triangular, teeth are not visible. Antennae geniculate. Scape attached at some distance from clypeus, protrudes far beyond the occipital margin of the head, 1.1–1.4 times as long as head. Joints of funiculus about 2.5 times longer than thick. Alitrunk a little wider than head. Scutum in side view feebly convex above and rounded anteriorly, not over−hanging pronotum in dorsal view. Propodeum seems to be flat in side view (it is not visible in side view in any specimens). Legs rather short and thick. Petiole without scale or node, a little longer than wide and high. Gaster oval.

Forewing with closed cells 1+2r, 3r, with no closed rm and mcu. Pterostigma narrow. Sections 5RS and 4M with joint start (rs−m lost). Cell 3r comparatively narrow, 5RS bent into 3r. 1RS and 1M form united transverse vein; 1M shorter than 1RS. 1RS inclined, forming acute angle with R; 2r−rs inclined.

Section RS+M (delimiting cell 1+2r from below) bent.

Major worker ( Fig. 4C ).—Only one head is preserved. HL = 1.3 mm. Head as long as wide, narrower in front than behind, with rounded occipital corners and feebly convex occipital margin. Eyes oval, convex, 0.3 times as long as head. Anterior margin of clypeus rounded. Mandibles elongate, dentate. Scape attached at some distance from clypeus, far protrudes beyond the occipital margin of the head, 1.15 times as long as head.

Minor worker ( Fig. 4D ).—BL = 5 mm, HL = 0.5 mm. Head about as long as wide, with convex sides, smoothly rounded occipital corners and feebly convex occipital margin. Anterior margin of clypeus rounded. Frontal lobes parallel. Eyes oval, situated on the midlength of head; maximum eye diameter about one fourthhead length. Mandibles long, about half head length, triangular, with long apical teeth and more short acute teeth on the masticatory margin. Scape attached at some distance from clypeus, protrudes far beyond the occipital margin of the head, 1.5 times longer than head. Joints of funiculus about 2.5 times longer than thick. Dorsal part of alitrunk and part of petiole destroyed. Legs rather short and thick, shorter than alitrunk. Petiole seems to be without scale or node, narrower in front than behind. Presumably these workers were able to elevate their gaster, but not as good as living species and fossil O. brischkei . Gaster oval.

Dimensions (mm).—PE−2000/8 (♀, holotype): AL = 4.2, HL = 2.0, SL = 2.2, FWL = 10.6; PE−1992/253 (♀, paratype): AL = 3.1; HL = 1.7, HW = 1.7, SL = 2.4; PE−1994/159 (♀, paratype): AL = 3.9, HL = 2.0, HW = 2.1, FWL = 11.4; PE−2000/1947 (major worker, paratype): HL = 1.3, HW = 1.3, SL = 1.5, MdL = 0.67, ED = 0.36; PE−2000/1948 (minor worker, paratype): AL = 1.5, HL = 0.5, MdL = 0.51, SL = 1.4, ED = 0.24, F3L = 1.2; PE−2000/1951 (♀, paratype): AL = 3.2, HL = 1.7, HW = 1.6, SL = 1.8.

Remarks.—Described workers are different in size and proportions. However, similar differences between major and minor workers from the same colony are known in both Recent species and Miocene Oecophylla leakeyi ( Wilson and Taylor 1964) .

Figures

Fig. 4. Weaver ant Oecophylla eckfeldiana Dlussky sp. nov., Eckfeld, middle Eocene. A. Gyne, holotype PE−2000/8. B. Gyne, paratype PE−1994/159. C. Head of major worker, paratype PE−2000/1947. D. Minor worker, paratype PE−2000/1948. Photographs (A1–D1) and drawings (A2–D2).