Mertovia sustai ( Kukalová, 1958 ) Prokop & Nel, 2007

Prokop, Jakub & Nel, André, 2007, An enigmatic Palaeozoic stem-group: Paoliida, designation of new taxa from the Upper Carboniferous of the Czech Republic (Insecta: Paoliidae, Katerinkidae fam. n.), African Invertebrates 48 (1), pp. 77-86 : 79-81

Mertovia sustai ( Kukalová, 1958) , comb. n.

v

Figs 2, 3

Protoblatoid sp. ( Cacurgidae ): Susta 1928: 414, pl. 17, fig. 8.

Holasicia sustai: Kukalová 1958: 943 , fig. 4.

Redescription: Distal two-thirds of fore wing with dark coloration, no spot or other colour pattern, with clearly visible reticulate venation (so-called ‘archaedictyon’) and rather thick membrane; fragment 52 mm long, probable complete length about 75 mm, maximum width 24 mm; area between C and ScP 4.4 mm wide, with net of small cells and veinlets in basal half and 4 or 5 weak branches of ScP in distal half; ScP clearly concave, ending on costal margin a little above wing apex; RA convex, straight and simple, with no branches, probably ending well before wing apex; RP diverging from R about 54.4 mm from wing apex, basally with neutral convexity and clearly concave in its distal half, with net of veinlets between it and RA and between it and M; RP simple, without clear distal branches, parallel to RA, probably reaching wing margin at wing apex; base of M poorly preserved, with convex MA between M and R not visible; MP with neutral convexity, divided into two (maybe three) posterior branches in its distal half; very strong convex ‘arculus’ between CuA and MP, about 53.5 mm from wing apex, opposite base of RP; CuA convex, with 5 or 6 posterior branches ending in CuP or in posterior wing margin; several oblique veinlets between CuA and MP and three anterior branches emerging from CuA distally, with apparent trichotomy between first anterior branch of CuA, main CuA and posterior branch of CuA; point of separation between CuA and CuP not preserved, but very basal; CuP strongly concave; three convex anal veins partly visible.

v Holotype: specimen B13189, imprint of the distal two-thirds of well preserved fore wing (originally Susta coll.). CZECH REPUBLIC: Upper Silesian Coal Basin , Hlubiná Pit in Karviná , hanging wall seam (No. 24); Upper Carboniferous, Westphalian A (Langsettian), Upper Suchá Beds (Member), Karviná Formation. Discussion: The description of H. sustai was originally based only on a photograph of

v

‘ Protoblatoid sp.’ from Susta’s work (1928: 414, pl. XVII, fig. 8), because at that time it was impossible to locate the specimen within the collection. Nevertheless , Kukalová believed that one day it could be recovered in the collection of the Municipal Museum in Ostrava. Subsequently, the missing holotype specimen did reappear during the transfer of the collection to another site. This rediscovery enabled a detailed study of the wing venation ( Figs 2, 3 ) and subsequent redescription .

The organisation of the median vein with a strong convex veinlet (arculus) between it and a clearly convex cubital vein, together with the absence of a developed convex vein MA corresponds to the ‘paoliid line’ pattern of wing venation of Kukalová-Peck and Brauckmann (1992, fig. 41). Such a convex arculus is also present in some taxa currently included in the Grylloblattodea, but they have a well developed convex MA, unlike this fossil. Those authors included the following families in the ‘paoliid line’: Paoliidae Handlirsch, 1906 , Eucaenidae Handlirsch, 1906 , Strephocladidae Martynov, 1938 , Blattinopsidae Bolton, 1925 , Synomaloptilidae Martynov, 1938 , and Cymbopsidae Kukalová, 1965 .Among these families, the Eucaenidae , Blattinopsidae , Strephocladidae , and Cymbopsidae strongly differ from Mertovia in their RP with numerous posterior branches. Carpenter (1992) included the Synomaloptilidae in the order Caloneurodea Handlirsch, 1937 but Béthoux et al. (2004) excluded them from this order. Rasnitsyn ( Rasnitsyn & Quicke 2002) transferred them to the superorder Hypoperlidea Martynov, 1928 . The medio-cubital pattern of Synomaloptila Martynov, 1938 remains poorly known but it differs from Mertovia in its cubital vein (CuA?) with only two distal branches ( Carpenter 1992, fig. 128.1; Rasnitsyn & Quicke 2002, fig. 121).

Kukalová-Peck and Brauckmann (1992) added Limburgina Laurentiaux, 1950 , but Béthoux and Nel (2002) noted that it is impossible to attribute it to the ‘paoliid line’ or to the Archeorthoptera Béthoux & Nel, 2002. The radial area of Mertovia is completely different from that of Limburgina . Kukalová-Peck and Brauckmann (1992) also included Heterologopsis in the ‘paoliid line’ but Béthoux and Nel (2002) demonstrated that it is an Archeorthoptera.

Rasnitsyn ( Rasnitsyn & Quicke 2002) considered the Paoliidae to be the most inclusive group of the Pterygota, and as a unique family of the order Paoliida . Thus he did not follow the hypothesis of Kukalová-Peck and Brauckmann (1992) and considered the ‘arculus’ sensu Kukalová-Peck and Brauckmann (1992) as a very short vein M5. He also indicated that the Paoliida have no synapomorphies, which makes the characterisation of this order particularly difficult. Therefore, the phylogenetic relationships of the Paoliidae remain controversial and unresolved. Nevertheless, the wing venation of Mertovia is very similar to those of some Paoliidae like Zdenekia or Paolia , at least in the organisation of the cubito-median veins and the long RP with few apical branches.

Rasnitsyn ( Rasnitsyn & Quicke 2002) included eight genera in the Paoliidae . Zdenekia shares with Mertovia a ScP separated from RA, but it is distinctly shorter, not reaching the wing apex, and unlike Mertovia its RP has three distal posterior branches ( Kukalová 1958, text-fig. 1). The ScP of Holasicia , Pseudofouquea , Paoliola , Olinka , and Paolia ends in RA and the RP has numerous posterior branches ( Melander 1903; Kukalová 1958, text-figs 3, 5, 9–12; Maples 1989, 1991). Kemperala also has a ScP ending in RA, but the RP in its fore wing is apparently simple and vanishes in the area between RA and M ( Brauckmann 1984; Brauckmann et al. 1985).

Unlike Mertovia , Sustaia has a ScP ending in RA, but even if its RP is poorly preserved, it has no posterior branches in nearly all its length, as in Mertovia ( Kukalová 1958, text-fig. 6, pl. 2, fig. 1). Another difference is the presence of numerous small branches of the anal vein in Sustaia , which is not apparent in Mertovia .

Carpenter (1992) considered the genus Paolekia Riek, 1976 , originally included in the Paoliidae , as a ‘ Protorthoptera of family uncertain’. The difference between Paolekia and Mertovia lies in the wing apex, the RP of Paolekia having no fewer than four main branches ( Riek 1976).

Handlirsch (1911) described the monotypic family Schuchertiellidae on the basis of a very incomplete wing base. Carpenter (1992) considered Schuchertiella Handlirsch, 1911 as incertae sedis. It has a strong oblique veinlet between a (probable) median vein and a (probable) cubital vein, but nothing is known about the convexity of these veins. Thus, it is not possible to determine if the family Schuchertiellidae belongs to the ‘paoliid line’ or to the Archaeorthoptera. Nevertheless, it differs from Mertovia in its basally forked alleged median and cubital veins.

Figures

Figs 2, 3. Mertovia sustai (Kukalová, 1958), comb. n. (Paoliidae), photograph and line drawing of holotype specimen B13189, collection of the Municipal Museum of Ostrava.