Triassologus biseriatus Riek 1976
Creators: name: Béthoux, Olivier
name: Anderson, John M.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Odonata
Triassologus
Triassologus biseriatus

description: Triassologus biseriatus Riek, 1976
(Figs 4-6A)
Triassologus biseriatus Riek, 1976: 793, text-fig. 1, pl. 1, fig. 5. — Bechly 1997: 56.
Reisia rieki Deregnaucourt, Wappler, Anderson & Béthoux, 2017: 615, figs 1-2, n. syn.
EXAMINED MATERIAL. — Holotype, specimen BP/2/20948 (left wing in ventral aspect; Fig. 4A, B); and specimens PRE/F/5118 (Fig. 4D, E) and PRE/F/10125 (Fig. 5B, C) (all specimens, Anderson collection, Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa).
TYPE LOCALITY AND STRATIGRAPHY. — The holotype and the specimen PRE/F/10125 were found at the ‘ Birds River’ locality (locality code Bir 111; see Anderson & Anderson 1984); material described by Deregnaucourt et al. (2017), Kapokkraal and Aasvoëlberg localities (Kap 111 and Aas 411, respectively); and specimen PRE/F/5118, Hlatimbe Valley (Hla 213); all South Africa; Molteno Formation; lower Carnian, Upper Triassic (Anderson et al. 1998).
EMENDED DIAGNOSIS. — Maximum width about 17 mm in forewing and about 19.5 mm in hindwing (about 24 mm in Triassologus aveyri n. comb., known from a putative forewing), forewing length about 110 mm.
SPECIMEN DESCRIPTIONS
Specimen PRE/F/5118 (Figs 4D, E, 6A)
Adpression preserving a left wing in dorsal (PRE/F/5118b; wing basal and median parts; extreme base, most of posterior area, and apical area missing) and ventral (PRE/F/5118a; about the first wing third, with portion of posterior wing margin missing opposite the pons) aspects; preserved length 84.5 mm, estimated total length about 110 mm; preserved maximum width 13.6 mm, estimated total maximum width about 16.0 mm; petiole 3.5 mm wide; area between anterior wing margin broad (maximum width 2.9 mm); MA 1.0 mm long between its origin (from RP+MA) to its point of connection with the pons; distal to the pons and basal to the nodus, RA, RP and MA running very close to each other but distinct; nodus located 33.7 mm from wing base; nodal and sub-nodal cross-veins short, moderately strong, sub-aligned, oblique; RP1+2/ RP3+4 fork located shortly after sub-nodal cross-vein; RP1+2 19.3 mm long; first I- between Irp 1 -rp 2 and RP2 seemingly emerging from RP2; first I- in the area between RP3+4 and MA originating 13.6 mm distal to the RP1+2/RP3+4 fork; pons oblique, 2.5 mm long; MP/Cu+AA fork opposite that of RP/MA; MP without obvious preserved branch; Cu+AA 2.8 mm long, Cu 1.6 mm long; in CuA-CuP area, the first 2 I- rectilinear and seemingly originating from CuA, the third I- originating as convex element shortly turning concave (possibly fused with a CuA branch at its origin); CuA branches zigzagging and seemingly originating from cross-venation; CuP and AA posteriorly pectinate; CuP curved, with 6 branches preserved (probably 7 in total), with intercalary veins between them; AA sigmoidal, with a maximum of 3 cells between it and the posterior wing margin; posterior wing margin forming a sharp angle opposite the RA/RP+MA fork.
description: Published as part of Béthoux, Olivier & Anderson, John M., 2023, New light shed on Triadophlebiomorpha wing morphology and systematics (Insecta: Odonata), pp. 479-496 in Geodiversitas 45 (17) on pages 488-490, DOI: 10.5252/geodiversitas2023v45a17, http://zenodo.org/record/8399030