Sylviodes perloides Martynov, 1940

Storozhenko, S. Yu. & Aristov, D. S., 2021, The latest record of the genus Belmophenopterum (Eoblattida: Mesorthopteridae) from the Middle Triassic of Kyrgyzstan, Far Eastern Entomologist 437, pp. 31-36 : 32-33

Sylviodes perloides Martynov, 1940

Figs 1, 2

NOTES. It is a type species of the genus Sylviodes . The holotype of this species was redescribed and illustrated by Aristov (2004). In the collection of the Paleontological

Institute a well preserved forewing of S. perloides from the type locality of Tshekarda is found ( Figs 1, 2 ). It allows clarify the taxonomic position of the genus Sylviodes , which was placed in its own family Sylviodidae (Martynov, 1940) , in Sylvaphlebiidae (Sharov, 1961;

Storozhenko, 1998), or in the family Ideliidae (Aristov, 2004) . The type species of Sylviodes is characterized by follow combination of forewing characters: SC reaching anterior wing margin distal to the second third of wing length; veinlets between anterior wing margin and

SC well developed, simple, connected by few cross-veins; R reaching apical margin of wing;

RS originate from R at the first third of wing length, with branches reaching the anterior wing margin; M forked earlier than R; MP desclerotized at the middle of wing; CuA not divided into anterior and posterior branches and forming a comb of branches directed to the posterior margin of wing (while in Sylvaphlebiidae CuA distinctly divided into CuA 1 and

CuA 2); area between CuA and CuP without posterior branches of CuA (while such branches present in Ideliidae ). All these characters are typical for Mesorthopteridae (Storozhenko,

1998; Aristov & Storozhenko, 2013); therefore Sylviodes undoubtedly belongs to this family.

graph; 2 – reconstruction.

Figures

Figs 1, 2. Sylviodes perloides Martynov, 1940 (PIN no. 1700/3991, forewing; Russia: Perm region, Suksun district, left bank of the Sylva River near the village of Tshekarda, Tshekarda locality; Lower Permian, Kungurian Stage, Koshelevka Formation): 1 – photo-