Revision of the Hylicellidae of the Late Triassic of Queensland (Hemiptera Cicadomorpha: Hylicelloidea) Author Lambkin, Kevin J. text Zootaxa 2020 2020-06-12 4790 3 525 539 journal article 10.11646/zootaxa.4790.3.7 1175-5326 3891303 F011C13E-8E90-45D8-ABA3-B7D58582648A Mesocixiodes Tillyard, 1922 Mesocixiodes Tillyard, 1922: 462 . Type species. Mesocixiodes termioneura Tillyard, 1922 , by original designation. Emended diagnosis. Tegmen c . 3.5 times longer than wide, finely to somewhat coarsely punctate and tending to irregularly transversely rugose, extreme apical area possibly less so; costal margin broadly rounded, apex narrowly rounded; peripheral membrane of even width; costal space c . 3 times as wide as medial cell; R and M separating near apex of basal cell; basal cell quite broad proximally, slightly tapering and closed distally by a fusion for a short length of M and CuA; primary fork of R just before tegmen length, far basal to primary fork of M which is well beyond primary fork of RA and just proximal to very shallow CuA fork; RA 1 simple, obliquely angled towards anterior margin; RA 2 stem directed apically, more or less parallel with costal margin, with 4 or 5 long, sub-equal pectinate branches directed antero-apically; RA 1 + RA 2 field occupying entire antero-apical margin; RP deeply forked; one ir , running from RA 2 to RP 1 ; RP 2 fused with M 1+2 for a short length ( RK1 and RK2 ), or separate, with a single r-m , in line with ir ( holotype ); M with 4 or 5 branches; im between M 2 and M 3 or M 3+4 ;intra-medial cell quite broad but very small, c . 2 times longer than wide, occupying a very small portion of post-nodal area; CuA branches short, CuA 1 strongly angled at m-cua which joins M 3+4 around midpoint of intra-medial cell; crossvein field tending to alignment at level of claval apex, thus creating a fairly even series of long, sub-equal apical cells; clavus not preserved . Notes. Mesocixiodes was placed by Tillyard (1922 , 1926 ), Becker-Migdisova (1962a) , and Jell (2004) in Cixiidae (Fulgoroidea) , by Handlirsch (1939) in Fulgoridae , by Evans (1956) in Chiliocyclidae , and was considered by Carpenter (1992) as ‘Family uncertain’. It was transferred to Hylicellidae by Hamilton (1992) . It differs from all other hylicellids in the very late forking of M, well distal of that of RA, the very small intra-medial cell, and the tendency to alignment of the crossvein field at the claval apex to create a fairly even series of long, sub-equal apical cells.