Cretobibio rasnitsyni, LUKASHEVICH & AMORIM & RIBEIRO, 2021

LUKASHEVICH, ELENA DMITRIEVNA, AMORIM, DALTON DE SOUZA & RIBEIRO, GUILHERME CUNHA, 2021, A Gondwanan record of the extinct genus Cretobibio (Diptera: Bibionidae), Palaeoentomology 4 (5), pp. 468-474 : 469-471

Cretobibio rasnitsyni sp. nov.

( Fig. 1 )

Material. Holotype, male. CCNH-139, housed at Centro de Ciências Naturais e Humanas , Universidade Federal do ABC, Santo André, São Paulo, Brazil.

Etymology. The species epithet honors Prof A.P. Rasnitsyn, an eminent Russian paleontologist, for all his collaboration in the study of insect fossils worldwide.

Diagnosis. Wing with extremely short distal section of M 3+4.

Locality and horizon. Crato Formation. Brazil, Ceará, Nova Olinda (07°05′30ʺ S, 39°40′46ʺ W), Pedreira Três Irmãos; upper Aptian, Lower Cretaceous .

Description. Male. Small, total length, 4.4; thorax length, 1.4; wing length, 3.9; wing maximal width, 1.1; abdomen length, 2.8. Head. Head height smaller than thorax height. Antenna short, flagellomeres not discernible. Thorax. Scutum short, arched. Legs. Tibial spurs not discernible. Tarsi short. Wing. C ending beyond tip of R 5, close to wing apex; Sc ending just beyond midwing. Pterostigma large, pale brown. R 1 and R 4+5 strong, R 1 ending in C level with M 1+2 furcation. Basal section of Rs oblique, long, 4x longer than r -m. Slightly curved R 4+5 forked clearly distal to tip of R 1, reaching margin before wing apex; R 5 3.7x longer than short R 4, R 5 ending in C level with M 2 tip, slightly curved. Stem M more sclerotized basally to insertion of r -m, weaker more distally. M 1+2 fork narrow, 1.4x longer than R fork and 5x longer than distal section of M 3+4. Basal section of M 3+4 gently arched, level with tip of R 1, near to M 1+2 furcation; m -cu very long, 3.5x longer than distal section of M 3+4. Not possible to recognize microtrichia on wing membrane. Terminalia . Hypopygium poorly preserved, compact, gonocoxite massive, gonostylus well-developed, short, slightly elongate, probably digitiform (only apex visible).

4+5

Remarks. The new species differs from the type species in extremely short distal section of M 3+4 which is subequal to m -cu in C. montsecensis . Wing of C. rasnitsyni sp. nov. male is larger than in type species, based on female (3.9 instead of 3.0–3.2) although usually females are larger.

Figures

FIGURE 1. Male of Cretobibio rasnitsyni sp. nov., holotype CCNH-139. A, Total view. B, Body with antennae (An) and gonostyli (Gs) marked. C and D, Wing. Scale bars = 1 mm.