Revision of the enigmatic insect family Anthracoptilidae enlightens the evolution of Palaeozoic stem-dictyopterans Author Guan, Zhaoying Author Prokop, Jakub Author Roques, Patrick Author Lapeyrie, Jean Author Nel, André text Acta Palaeontologica Polonica 2016 2015-01-19 61 1 71 87 http://dx.doi.org/10.4202/app.00051.2014 journal article 294715 10.4202/app.00051.2014 f940c568-9574-4638-861a-fe7a7f43ae97 1732-2421 10980713 Pseudomesoptilus sellardsi ( Lameere, 1917 ) comb. nov. Fig. 5 . Type material : Holotype : MNHN R51350, imprint of fragmentary thorax with a pair of forewings. Type locality : Commentry Basin , Allier department, France . Type horizon : Stephanian , Carboniferous (= Gzhelian , Upper Pennsylvanian ). Material .— Type material only. Diagnosis .—Forewing ca. 30 mm long; RP distally pectinate ending with five simple branches; CuA with five main anterior branches. Description .—Imprint of two forewings attached to thorax fragments. Forewing with apex and posterior margin partly missing, and posterior base partly missing; wing 30.7 mm long, 8.9 mm wide; straight, concave ScP with several anterior branches reaching costal margin; area between ScP and costal margin with numerous crossveins and veinlets, 1.2 mm wide; ScP parallel to radius, 0.8 mm apart, ending on RA 20.9 mm from wing base; radial stem straight; RA convex, straight and simple, ending 1.7 mm from anterior wing margin; two main veins emerging separately from radial stem, viz. basal (MA?) plus distal concave RP , first one simple and straight, emerging 9.8 mm from wing base, second main branch emerging 16.3 mm distally, posteriorly pectinate into five branches; convex median vein straight and simple, emerging from a common stem with radius, 6.2 mm from wing base, with a rather strong veinlet between it and radius just basal of most basal posterior vein (MA?) emerging from radius, this veinlet could be anterior branch of median vein reaching radius and re-emerging just distally; distal part of median vein only forked near posterior wing margin; median vein parallel with first vein (MA?) emerging distally from radius and well separated from CuA at its base; convex CuA anteriorly pectinate with five main branches less convex in distal parts, resulting into six or seven branches ending on wing margin; concave CuP simple and curved, CuA and CuP emerging from a common stem Cu; several crossveins between CuP and CuA in a 3.2 mm wide area; areas between CuA, CuP , anal and posterior margin poorly preserved and posterior wing margin partly missing in both wings; one visible anal vein, simple. Remarks .—This taxon strongly differs from Mesoptilus dolloi (and all other Anthracoptilidae ) in the presence of two main veins (MA? and RP ) emerging separately from radius; RP emerging distal mid part of wing, instead of in the basal third or fourth; absence of brace or approximation between RP and median vein or between median vein and CuA. Nevertheless it shares with the Anthracoptilidae (especially Strephocladus ) the presence of a strongly convex stem CuA from which emerge a series of five more concave anterior branches, ScP ending on RA, area between ScP and C with numerous anterior veinlets emerging from ScP , branches of main veins all parallel and generally simple, with a net of rectangular cells between them. Thus, if we provisionally maintain it in the Anthracoptilidae , it is necessary to transfer it into a new genus different from Mesoptilus . Fig. 5. Forewing of anthracoptilid insect Pseudomesoptilus sellardsi ( Lameere, 1917 ) comb. nov. from Stephanian of Commentry Basin, France, holotype R51350, photograph ( A ), line drawing ( B ). Stratigraphic and geographic range .—Stephanian, Carboniferous (= Gzhelian, Upper Pennsylvanian), France .