Workings for coal in the vicinity of Wigan and Manchester, Lancashire, UK yielded exceptional Late Carboniferous faunal material in the early part of the 20^th century, in particular from the Sparth Bottoms locality [20]. A number of new sites were investigated and documented between 1995 and 2005 [2] and [3], in particular the Bickershaw Colliery spoil tips and opencast pits at Westhoughton, Cranberry Lea Farm, and Crock Hey (Fig. 1 and Fig. 2).

Anderson et al. [4] documented the stratigraphic succession exposed in the Westhoughton opencast pit, which was accessible from mid-1995 to early 1997. A 22-m interval here includes three main coals (Fig. 3). Above the thickest of the coals, the ‘Wigan Four Foot’, an 11-m coarsening-upward succession can be seen, recording delta progradation into a lake. Comparable coarsening-upward patterns are commonly seen in other exposures in the area, including that of the more recently available Crock Hey opencast (Fig. 4 and Fig. 5), and above a coal at Crock Hey, with numerous siderite concretions present in the mudstones (Fig. 6).

The homoiopterid from the Somerset Coalfield was found over 24 years ago in Roof Shales (mudstones) near Radstock on the tip of the former Kilmersdon Colliery (National Grid Reference ST 682 536). Like the neighbouring Lower Writhlington Colliery, the pit worked the No. 10 coal in the lower part of the Upper Asturian Farrington Formation prior to closure in 1973 [15]. At Kilmersdon, however, the seam was worked longer (1951–1973, [1]). E.A. and J. Brigid have collected a small arthropod fauna from the old tip comprising Blattodea, Phalangiotarbida and Xiphosura, of which the insects are the most common. An archaeorthopteran and a trigonotarbid have also been described from here [7] and [12]. The arthropods are usually tectonically deformed due to the Variscan Orogeny and associated with a lycopsid-dominated flora representing a flood-basin forest as at Writhlington. The palaeodictyopteran found by Mr Cooper is unusual in that it is not only a new record, but it is also associated with a filicopsid (pinnule of Lobatopteris vestita (Lesquereux) Wagner det. C. Cleal, written communication, 2005). It is, however, unreddened, so is unlikely to have come from much earlier tipping of the Lower Cantabrian Radstock Formation.

Family Homoiopteridae Handlirsch, 1906

List of genera after [11 ] supplemented in [9 ^* and 22⁺]: Adolarryia Kukalová-Peck & Richardson, 1983; Ametretus Handlirsch, 1911*; Amousus Handlirsch, 1911*; Boltopruvostia Strand, 1929; Homoioptera Brongniart, 1893; Larryia Kukalová-Peck & Richardson, 1983; Mammia Handlirsch, 1906*; Mazonopterum Kukalová-Peck & Richardson, 1983; Mazothairos Kukalová-Peck & Richardson, 1983; Paraostrava Prokop & Nel, 2004 ⁺ , Parathesoneura Sinitshenkova, 1977; Scepasma Handlirsch, 1911*; Thesoneura Carpenter, 1944; Turneropterum Kukalová-Peck & Richardson, 1983.

Genus Anglopterum gen. n.

Type species. Anglopterum magnificum sp. n. by original designation.

Etymology. Compound name Anglo- after the name of the country (England) and pterum from Latin for wing; masculine in gender.

Diagnosis. Homoiopterid genus based on wing venation: Anglopterum gen. n. differs from all other homoiopterid genera by a combination of the following characters: convex ScA reaching anterior wing margin beyond midlength; broad area between ScP and ScA with numerous oblique sigmoidal veins, RA simple; RP dichotomously divided in distal part of wing with four main branches; first branch of RP a long distance from the base of RP; area between RA and RP area with numerous long sigmoidal cross-veins and small cells; MA simple; MP area very broad with more than five branches; CuA simple, without strong basal anterior curve; a broad area between Cu (CuA) and M basal of fork of M; CuP with more than four branches; AA divided into three branches; AP with about seven branches, forming a large anal area; anal brace in the form of a convex ridge [19].

Anglopterum magnificum sp. n. (Fig. 7 and Fig. 8)

Description. Wing membrane probably originally hyaline; wing covered with a dense irregular venational network (‘archaedictyon’); convex ScA only partly preserved; concave ScP straight, running close to radius (R), and partly preserved, reaching anterior wing margin very distally, close to wing apex; area between ScP and ScA broad and with numerous oblique cross-veins; distal part of same area with several short cross-veins; RA and RP fused basally, separating at about 1/3 wing length from base; RA simple and straight, ending on anterior margin probably in wing apex; RA and RP area with numerous long sigmoidal cross-veins and small cells; RP dichotomically divided ending on posterior margin near wing apex with four main branches; first branch of RP a long distance (60 mm) from base of RP; stem of M basally curved, divided into MA and MP at about the same level as separation of RA and RP; MA simple, strongly curved basally, ending on posterior wing margin about 30 mm from wing apex; base of MP about 45 mm from wing base; first fork of MP 15 mm distal to its base; anterior branch of MP dichotomously divided four times, and reaching posterior wing margin with five main branches; posterior branch of MP divided into four main branches, second and third terminally twigged; MP area very broad and reaching posterior wing margin from 35 to 85 mm from wing apex; M and R very close for a short distance near their bases, opposite first fork of MP; stem of Cu divided into CuA and CuP about 30 mm from wing base; forks of Cu and of M rather distant, 17 mm apart; CuA simple, slightly curved, and ending on posterior wing margin about 95 mm from wing base; CuP slightly curved, more or less parallel to CuA and forked into two main branches; anterior branch of CuP terminally twigged, posterior branch dichotomously forked into three branches; stem of AA distinct and divided into three branches; AP area partly preserved, AP ending on posterior wing margin with about seven branches, forming a large anal area (hind wing); anal brace in the form of a convex ridge.

Dimensions. Holotype: length of fragment about 130 mm, probable total length about 145 mm (wingspan more than 300 mm). Paratype: length of fragment 103 mm.

Material. Holotype specimen in A. Tenny private collection, Lancashire, UK, a nearly complete hind wing in a half concretion; paratype specimen RS.UC.93 in RDA. Smith private collection, The Netherlands, median part of a wing in a concretion.

Type locality. Holotype: Crock Hey opencast pit (accessible from 2001 until 2005), paratype: Westhoughton opencast pit (accessible from 1995 to 1997, described in [3], Lancashire, UK.

Type strata. Holotype: concretion in mudstone above Crock Hey Coal 2 (tentatively identified as the Wigan Four Foot seam); Paratype: concretion in mudstone above the Wigan Four Foot Coal (described in [4]). Langsettian (Westphalian A), Late Carboniferous.

Etymology. After the wonderful state of preservation of one of the specimens.

Discussion. These fossil wings appear very similar to the hind wing of the homoiopterid Mazonopterum wolfforum Kukalová-Peck and Richardson, 1983 [19 (Fig. 8 and Fig. 9)]. The few differences are as follows: presence of long sigmoidal veins in area between ScA and ScP, instead of short simple cross-veins; first branch of RP very far from its base, distal of midway between base of RP and second branch of RP in Anglopterum magnificum gen. et sp. n. instead of being before midway in M. wolfforum; forks of Cu and M well apart instead of being rather close; 2/3 rows of cells between CuA and MP in the narrowest part of area between them, instead of only one; CuA less curved basally; area between RA and RP broad and with network of long sigmoidal veins instead of being narrow with only simple cross-veins or reticulate with irregular small cells; RP with only four main branches instead of seven; wing shorter and broader.

Among the Homoiopteridae with CuA simple or with weak terminal branches, Ostrava Kukalová, 1960 shares with Anglopterum gen. n. the absence of a strongly curved CuA, but differs from Anglopterum and Mazonopterum in the absence of a broader area between M and Cu (CuA) basal of the fork of M. Parathesoneura Sinitshenkova, 1977 and Scepasma Handlirsch, 1911 have an MP with few branches (less than four) instead of nine main branches as in Anglopterum. Lastly, Paraostrava Prokop and Nel, 2004 differs from Anglopterum in the presence of a terminal twig of CuA, seven main branches of MP (nine in Anglopterum), absence of a broad area between M and Cu basal of M fork, and probably more basal ending of ScA in costal margin.

Remarks. The other material is very similar to the holotype, differing from the latter in the forks of Cu and M being closer. This character alone is not sufficient for specific separation, as a similar difference occurs in Homoioptera vorhallensis Brauckmann and Koch, 1982 [8 (Figures 11b and 12b),10]. The two wings were probably of about the same length.

Genus Mazonopterum Kukalová-Peck and Richardson, 1983

Type species. Mazonopterum wolfforum Kukalová-Peck and Richardson, 1983

Mazonopterum cf. wolfforum Kukalová-Peck and Richardson, 1983 (Fig. 9 and Fig. 10)

Description. Posterior-basal part of hind wing (large, broad anal fan present); wing membrane with well-developed archaedictyon [16 (pl. 1, fig. 11)]; Sc and R areas poorly preserved except for tubercles in ScA; stem of M basally curved, dividing (asymmetrically) into MA and MP; M branching distal of Cu but MP dividing opposite the posterior branch of CuP; basal portion of CuA simple, strongly curved; CuP slightly curved, more or less parallel to CuA and dividing into two main branches; posterior branch of CuP dichotomously forked into three branches; AA double corrugated and evidently dividing into two paired branches; AP ending on posterior wing margin with eight main branches (one end-twigged), forming a large anal area; anal brace (b) gently curved and in the form of a convex fold.

Dimensions. Length of fragment: 48 mm.

Material. Specimen In. 64687, Natural History Museum, London, coll. R. Cooper of Tewkesbury, Gloucestershire, UK; part and counterpart of hind wing base (partly obscured by fern pinnule) in mudstone.

Type locality. Kilmersdon Colliery tip, near Radstock, Somerset, UK.

Type strata. Roof Shale probably above the No. 10 coal, Farrington Formation, Upper Asturian (late ‘Westphalian D’), Late Carboniferous (Middle Pennsylvanian).

Discussion. The pattern of the preserved veins is similar to that of Mazonopterum and Anglopterum, especially the cubital and median veins, and notably in the presence of a broad area between Cu and M basal of the fork of M (into MA and MP).

This specimen shares with M. wolfforum the basal fork of AA being in a very basal position; CuA having a strong anterior curve at its base; and one row of cells between CuA and MP in the narrowest part of the area between them. Thus it could belong to the same genus, but the lack of information on the subcostal and radial areas precludes a more definite conclusion as to its taxonomic position. It is about the same size (circa 4-cm wide) as M. wolfforum, but exact comparison with the latter is impossible because of the lack of important structures (costal, radial, and median areas) and tectonic deformation (oblique anterior-posterior extension).

This specimen differs from M. wolfforum in the following: AA is narrower with fewer distal branches; CuP is distinctly broader (more branched); the archaedictyon in AA has more rows of cells – commonly up to five [14 (Fig. 7)], compared with three or four in the latter species [19 (Fig. 8)].

Finally, due to the fragmentary state of preservation we prefer to leave this specimen attributed as Mazonopterum cf. wolfforum rather than establishing a new species.

Anglopterum magnificum gen. et sp. n. and M. cf. wolfforum are the first described homoiopterid species from the British Isles. They show a similar structure of the wing venation to Mazonopterum wolfforum (Westphalian D/ Cantabrian, Mazon Creek, Illinois, USA). The close affinities of these taxa support the well-known Euramerican connection during the Late Carboniferous. Other non-marine arthropod species such as the chelicerates Euproops danae (Meek & Worthen, 1865), Pleophrynus verrucosa (Pocock, 1911) and Adelophthalmus imhofi Jordan & Meyer, 1856 are known both from Radstock and Mazon Creek [2], [12] and [21].