Grimmenia tillyardi, Kopeć, Krzemiński, Skowron & Coram, 2017

Kopeć, Katarzyna, Krzemiński, Wiesław, Skowron, Karina & Coram, Robert, 2017, The genera Architipula Handlirsch, 1906 and Grimmenia Krzemiński and Zessin, 1990 (Diptera: Limoniidae) from the Lower Jurassic of England, Palaeontologia Electronica 15 (32), pp. 1-7 : 4-5

Grimmenia tillyardi n. sp.

Figure 4

zoobank.org/ 600AC2CE-0C88-445A-8E19-1C92A111F3CE

Etymology. The species name is dedicated to Robin John Tillyard, the palaeoentomologist who described the first Limoniidae from the Jurassic of England.

Holotype. I. 3328 from Alderton Hill ( Gloucester ), Upper Lias ( Lower Jurassic : Toarcian), housed in the Natural History Museum, London.

Diagnosis. Sc terminates opposite fork of Rs into R 2+3+4 and R 5; R 2+3+4 long, distinctly longer than in other known species of the genus, equal to R 2+3 and R 3 combined; Rs almost twice as long as R 2+3+4; d-cell short and wide, which clearly differentiates this species from all congeners.

Description. Wing length 3.8 mm; Sc ends opposite bifurcation of Rs into R 2+3+4 and R 5; cross-vein sc-r situated its own length before tip of Sc; R 1 ends opposite one third length of R 2+3 and R 3 combined; R 2+3+4 very long, as long as R 2+3 and R 3 combined; Rs almost twice as long as R 2+3+4; R 4 equal in length to Rs and twice as long as R 2+3+4; d-cell 0.125 the length of the wing; almost rectangular, its upper part almost the same length as its basal part; top part of cross-vein m-m inclined towards the wing base; M 1 shorter than petiolus; m-cu situated towards distal end of d-cell, just before fork of M 3+4 into M 3 and M 4.

Remarks. Grimmenia tillyardi n. sp. is very similar to G. prima from the Toarcian of Grimmen, Germany ( Krzemiński and Zessin, 1990). However, it clearly differs from this species in its longer vein R 2+3+4; the shape of the d-cell, which is short and wide, and longer veins M 1 and M 2.

Figures

FIGURE 4. Wing venation of Grimmenia tillyardi new species. I. 3328, holotype.