Duraznoscytinum Lara, Cariglino & Zavattieri, 2023

LARA, MARÍA B., CARIGLINO, BÁRBARA & ZAVATTIERI, ANA M., 2023, Duraznoscytinum aristovi gen. et sp. nov., a new scytinopterid (Hemiptera: Cicadomorpha) from the Upper Triassic of Argentina, Palaeoentomology 6 (2), pp. 146-154 : 147-149

Genus Duraznoscytinum Lara, Cariglino & Zavattieri gen. nov.

Type species. Duraznoscytinum aristovi gen. et sp. nov., by present designation.

Etymology. Durazno – refers to Quebrada del Durazno locality and scytinum – to the Scytinopteridae , a typical Permo-Triassic hemipteran family.

Diagnosis. Only the forewing characters are known. Costal margin convex and thickened basally.Veins usually thick and costal area wide. Stem RA 2 simple. Stem M distally forking into four simple branches. Crossveins rpm joined R to stem M 1 and m-cua connects stem M 3 +M 4 to CuA 1. Claval area with Pcu and two anal veins. Pcu with S-shaped, reaching postclaval margin. A “Y” fork present in the anal area. Vein A 2 very close to postclaval margin.Anal angle about 133°. Slightly distinctly uniform punctate. Color pattern preserved.

Remarks. Duraznoscytinum gen. nov. is referred to Scytinopteridae Handlirsch, 1906 based on the following characters: forewing tegminous, costal margin thickened basally and costal area wide, basal cell gradually narrowing, stem of R, M and Cu come off separately from a point close to the base, branches of M and CuA short, and crossveins reduced ( Tillyard, 1919).

Duraznoscytinum gen. nov. differs from Scytinoptera Handlirsch, 1904 (Middle Permian to Middle–Late Triassic of Russia, Mexico, Kyrgyzstan, South Africa, and China) ( Martynov, 1928; Zhang et al., 2021) in: origin and length of R, RA, and RP; M with four branches apically; clavus elongated, anal angle about 133°; Pcu and A 1 with S-shaped; A 1 meeting A 2 forming a “Y” fork; color and ornamentation (granular) pattern preserved.

Duraznoscytinum gen. nov. can be distinguished from other known Triassic scytinopterid genera ( Table 1) by the following characters: from Mesoscytina Tillyard, 1919 , Eurymelidium Tillyard, 1919 , Apheloscyta Tillyard, 1922 (Upper Triassic of Australia and Argentina) in forewing size (~ 15 mm vs. 5–11 mm), costal margin convex (in Mesoscytina more convex), stem R short and straight (in Eurymelidium sinuous and in Apheloscyta gently curved basally), origin and length of RA and RP, stem M straight (in Mesoscytina , Eurymelidium , and Apheloscyta curved), number of M branches (in Eurymelidium and Apheloscyta two-branched, in Mesoscytina M threebranched), branches of CuA long, ornamentation and color pattern. Duraznoscytinum gen. nov. differs from Tipuloidea Wieland, 1925 , Argentinocicada Martins-Neto & Gallego, 1999 , and Cuyanoscytinum Lara, 2020 (Upper Triassic of Argentina) in forewing size (~ 15 mm vs. 18–27 mm), number of M branches (in Argentinocicada five/sixbranched, in Cuyanoscytinum M seven-branched),position of m-cua crossvein (in Tipuloidea and Argentinocicada m-cua connects medial cell to CuA 1, in Cuyanoscytinum stem M to CuA 1), and absence of medial cell ( Lara & Bashkuev, 2020).

Cacheutacicada Martins-Neto & Gallego, 2008 (Upper Triassic of Argentina) was placed by the authors as uncertain family position within Scytinopteroidea . However, the genus presents typical characters of Scytinopteridae Handlirsch, 1906 such as costal margin thickened basally and costal area wide, Sc reduced or absent, branches of M and CuA short, and crossveins reduced. Therefore, in this paper, we consider Cacheutacicada Martins-Neto & Gallego, 2008 as a scytinopterid, but distinct from Duraznoscytinum gen. nov. in forewing length (~ 15 mm vs. 22 mm) and position of m-cua (in Cacheutacicada m-cua joins stem M to CuA 1) ( Table 1).

In relation to the genus Potrerillia Martins-Neto & Gallego, 1999 (Upper Triassic of Argentina), we prefer maintaining its taxonomic position as doubtful due to the absence of diagnostic scytinopterid features in the specimen, which in our view presents more similarities with Dysmorphoptilidae (e. g., convex proximally costal margin, apical portion of CP directed to ScP, common stem R+M+CuA, CuA forked before veinlet m-cua) ( Szwedo & Huang, 2018; Lara et al., 2021).

On the other hand, according to Popov &Shcherbakov (1991), Scytinoptera distorta Riek, 1976 (Upper Triassic Molteno Formation, South Africa) belongs to the Progonocimicidae . However, some morphological characters (e. g., RP simple, M arising distant from base, branching distally, CuA connected to M slightly after its origin from R by a short crossvein m-cu, CuA leaving basal cell as separate stem) observed in this specimen are typical of Scytinopteridae . So, in this paper we include S. distorta Riek, 1976 as a scytinopterid member until new photos or specimens are available for further studies ( Table 1).