Toxorhina (Ceratocheilus) mexicana, Kopeć, Kania & Krzemiński, 2016

Kopeć, Katarzyna, Kania, Iwona & Krzemiński, Wiesław, 2016, New and little known crane-fly species of the genera Helius, Elephantomyia and Toxorhina (Diptera, Limoniidae) from Dominican and Mexican amber, Palaeontologia Electronica 13 (8), pp. 1-14 : 10-11

Toxorhina (Ceratocheilus) mexicana n. sp.

Figures 7 and 8

zoobank.org/ 031FC017-9417-4D28-9687-837BFEB0724C

Type material. Holotype: No. PI II 1870 (female); Mexican amber ( Lower Miocene ), Chiapas, Mexico; Natural History Museum, London, UK.

Etymology. The name of species is derived from Mexico, where the amber comes from.

Diagnosis. The Toxorhina (Ceratocheilus) mexicana n. sp. differs from all fossil and extant species from South and Central America by very short vein R 2+3+4, equal in length of vein Rs; cross-vein m-cu is positioned distinctly behind the bifurcation of Mb, it differ also by very elongated, narrow ovipositor.

Remarks. From South and Central America only two localities with fossil remains are known—Santana Formation and localities from where the Dominican amber comes from. To that day, only a few Limoniidae have been discovered from these localities. Hence, each new finding is very important and considerably enriches our knowledge about evolution of this family in the Neotropical Region. The new species, Toxorhina (Ceratocheilus) mexicana n. sp. is the first representative of Toxorhina Loew, 1851 from Mexican amber. Until now, only 11 species have been described from South and Central America, one of them from Mexico. In 2001, Podenas and Poinar noticed a partially preserved specimen of Toxorhina (Ceratocheilus) from the Dominican amber, with no preserved genitalia and unknown sex. During a few last years, any new Recent species of the genus have been described from the Dominican Republic. Description. The specimen is well preserved, but without part of a wing, the second wing is partially crinkled, 4.66 mm long. The body 7.10 mm long, dark brown, the basal part of tergites and sternites pale brown, the distal part of tergites and sternites almost black, ovipositor elongated. Head ( Figures 7.1 , 8.1 ): small, 0.37 mm long with very elongated rostrum 4.67 mm long ( Figure 7.2 ), rostrum slightly longer than wing length ( Figure 8.1 ), apical part of rostrum dainty with palpus relatively slender, probably 2-segmented ( Figure 8.2 ); antenna 0.81 mm long, 12-segmented (not well preserved); pedicel elongated, cylindrical; scape huge, conicle; flagellomeres short, barrel like, tapered to the end of antenna, with very long and conspicuous setae (verticils) toward the apical part of antennae. Thorax ( Figure 8.1 ): brown, legs very elongated, partially preserved in mentioned specimen, wing ( Figures 7.3 , 8.1 ) 4.66 mm long, 1.02 mm wide, vein Sc relatively short, vein Rs and basal section of R 5 almost equal in length, nearly straight, R 2+3+4 almost equal in length of Rs, d-cell elongated, twice as long as wide, M 3 approximately 1/3 longer than d-cell, m-cu behind the bifurcation of Mb, A 1 almost straight, A 2 slightly waved. Abdomen ( Figures 7.4 , 8.3 ): female genitalia: ovipositor very elongated, narrow and slender ( Figures 7.4 , 8.3 ), 1.58 mm long with hypogynal valves wide, cerci narrow, longer than hypogynal valves.

Figures

FIGURE 7. Toxorhina (Ceratocheilus) mexicana n. sp., No. PI II 1870 (female). 1, a drawing of the head (reconstructed) in lateral view; 2, a schematic representation of the relation between the length of palpi (p), antenna (a), rostrum (r) and head (h); 3, a drawing of the left wing venation; and 4, a drawing of the ovipositor in latero-ventral view.

FIGURE 8. Toxorhina (Ceratocheilus) mexicana n. sp., No. PI II 1870 (female). 1, a photograph of the body in lateral view; 2, a photograph of the apical part of rostrum in lateral view; and 3, a photograph of the ovipositor in latero-ventral view.