Piroutetia liasina Meunier, 1907

Béthoux, Olivier & Anderson, John M., 2023, New light shed on Triadophlebiomorpha wing morphology and systematics (Insecta: Odonata), Geodiversitas 45 (17), pp. 479-496 : 486

Piroutetia liasina Meunier, 1907

( Fig. 3 )

EXAMINED MATERIAL. — Holotype and only known specimen MNHN.F.B09711 (left wing in ventral aspect; Muséum national d’Histoire naturelle, Palaeontology collection, Paris, France; Fig. 3 ).

REMARKS

The redescription of the holotype (and only known specimen) of this species by Nel (1989) only needs a minor emendation, regarding the occurrence of a cross-vein more oblique than others in the distal part of the RA-RP1 area. Such a cross-vein commonly occurs in Triadophlebiomorpha ( Pritykina 1981). The excellent preservation of veins corrugation in the specimen makes it particularly interesting. It can be assessed that MP is branched distally, posteriorly pectinate, with a total of 4 branches. The first posterior branch of MP as identified by Nel (1989) is herein regarded as an intercalary vein occurring between the two branches of CuA, which is more consistent with: i) the lack of a concave base in connection with MP; ii) the position of this structure relative to the most distal (genuine) MP branches; and iii) the common occurrence of such Icua in Triadophlebiomorpha. The course of Irp 1 -rp 2 (expected to be convex) is not evident if considering veins elevation:our proposal ( Fig.3A ) supposes that it is alternatively convex and concave ( Fig. 3B ). A possible explanation is that Irp 1 -rp 2 is fused with a posteriorly pectinate I- that would have occurred between Irp 1 -rp 2 and RP2. Such a structured I- is known in Cladophlebia parvula Pritykina, 1981 (see original description), in which it seemingly originates from RP2. Moreover, it is separated from Irp 1 -rp 2 by a very narrow area. A fusion of the two structures, as proposed herein for Piroutetia liasina , is therefore plausible.

Figures

FIG. 3. — Piroutetia liasina Meunier, 1907, holotype, specimen MNHN.F.B09711: A, drawing of venation, with tentative reconstruction of wing base; B, C, photographs extracted from RTI file; B, light-mirrored; C, normals visualisation. Scale bar: 5 mm.