Costaclymenia Bed (Bed 2)

Encrusted on top of the underlying bed with Sp. muensteri orbiculare is a unit (Bed 2) with many crinoidal holdfasts in life position (Fig. 5a, insert), similar to those illustrated from older Famennian beds of the Jebel Bou Ifarherioun and Jebel Mech Irdane (Wendt, Aigner & Neugebauer, Reference Wendt, Aigner and Neugebauer1984; Wendt, Reference Wendt1988 a). They show irregular and branched shapes (Fig. 2c, insert), formed by repeated encrustation. Bed 2 consists of several depositional units. An irregular hardground surface with cavities is developed in the basal part (Fig. 5a, arrows) and formed the fundament for thin hematitic crusts. Above this hiatus surface, coarse crinoidal packstones follow. Fining upward gradings suggests storm sedimentation, which is supported by the fragmentation and only sub-rounded outline of crinoid ossicle pieces. Marginal microborings, probably by cyanobacteria, indicate an influx from a nearby shallow setting but there are no typical neritic faunas. The assemblage of Bed 2 contains ostracods, fragmented bivalves, rare small-sized gastropods, and ammonoids. Bioturbation is evident in the matrix-rich upper part. Reddish-brown to sporadically yellow-golden microstromatolites encrusted skeletal remains and caused cauliflower structures. They resemble Frutexites (Böhm & Brachert, Reference Böhm and Brachert1993) and were previously described by Préat, El Hassani & Mamet (Reference Préat, El Hassani and Mamet2008) and Hartenfels (Reference Hartenfels2011) from the higher Famennian of the Maider and Tafilalt. In general, laminated iron encrustations are regionally widespread in the Tafilalt (Wendt, Aigner & Neugebauer, Reference Wendt, Aigner and Neugebauer1984; Becker, Reference Becker1993, fig. 53; Becker et al. Reference Becker, Bockwinkel, Ebbighausen and House2000; Jakubowicz, Belka & Berkowski, Reference Jakubowicz, Belka and Berkowski2014) and indicate extremely slow depositional rates. Préat, El Hassani & Mamet (Reference Préat, El Hassani and Mamet2008) postulated that such crusts originated under dysaerobic conditions, which interpretation, however, was questioned by Koptíková et al. (Reference Koptíková, Bábek, Hladil, Kalvoda and Slavík2010) and Hartenfels (Reference Hartenfels2011), due to co-occurring normal benthic faunas. Grain margin solution, particularly between crinoid remains, is the result of diagenesis. Pseudopeloids occur only within ammonoid shells, where they were protected from diagenetic compression (cf. Hartenfels, Reference Hartenfels2011). The micritic matrix outside may have lost its original pseudopeloid structure by diagenesis. In summary, Bed 2 accumulated adjacent to a storm-swept crinoidal shoal (upper carbonate ramp). The hardground in the lower parts reflects an interval of regression and non-deposition. A second hardground is developed on the top surface, where corroded clymeniids and crinoid holdfasts (Fig. 2c, insert) suggest submarine carstification during long-lasting non-deposition.

Figure 5. Microfacies of upper/uppermost Famennian marker beds at Jebel Ihrs West. (a) Costaclymenia Bed (Bed 2, lower B. costatus Subzone), fining upwards sequence within a crinoidal (2) packstone with shell filaments (3), ostracods (4) and bioturbation (5) above an irregular hardground surface as evidence of submarine karstification (black arrows, figure width c. 30 mm). In situ crinoidal holdfasts (1) show irregular and branched shapes due to repeated encrustation (insert, figure width c. 32 mm); (b) Gonioclymenia Limestone (Bed 3, upper B. costatus Subzone), macrofossil-rich, oncolithic packstone with golden brown Frutexites encrustations (1), fragmented shells, crinoid remains (4), ostracods, solitary deep water rugose corals (2), trilobites (5), rare heterocorals (3, insert, 0.8 mm diameter) and minute gastropods (6); figure width c. 24 mm; (c) Kalloclymenia Limestone (Bed 4b, lower B. ultimus ultimus Zone), macrofossil-rich microbial packstone with crinoids (3), numerous sparite-filled fenestrae, fragmented ammonoids, ostracods, thin-shelled bivalves, rare trilobites, solitary rugose corals (1), heterocorals (2), bioclasts encrusted by brownish-black Frutexites-lamina, extremely rare oncolites, and angular quartz (silt) grains; figure width c. 27 mm; (d) Bed 5b (higher B. ultimus ultimus Zone), silty (see insert, figure width c. 2.5 mm) crinoidal (1) packstone with Frutexites encrustations, ostracods, shell filaments (2), rare trilobites, and bioturbation; figure width c. 14 mm).

Costaclymenia sp. (Fig. 2c) indicate the lower Dasbergian (of German substage terminology) or UD V-A. The rich conodont fauna (Fig. 6) include rare, slender pseudopolygnathids (Ps. primus tafilensis ssp. nov. and Ps. primus aff. tafilensis ssp. nov.) and a single B. costatus Morphotype 2, the index species of the B. costatus Subzone of the B. aculeatus aculeatus Zone (Fig. 7; Hartenfels, Reference Hartenfels2011). Consequently, the Dasberg Event Beds of the basal B. aculeatus aculeatus Zone (and Subzone), which are widespread in other Tafilalt sections (Hartenfels & Becker, Reference Hartenfels, Becker and Over2009), are missing locally in the highly condensed sequence, possibly at the hardground level. There is a dominance of Pa. gracilis gracilis and Neo. communis communis, followed in terms of abundance by simple bispathodids and spathognathodids (Branmehla and Mehlina). This faunal composition agrees with a moderately deep shelf setting (see conodont biofacies model of Sandberg, Reference Sandberg and Barnes1976).

Figure 6. Conodont record and biofacies at Jebel Ihrs West, beds 2 to 5b.

Figure 7. Correlation of upper/uppermost Famennian Tafilalt and supraregional conodont as well as ammonoid biostratigraphy.

Gonioclymenia Limestone (Bed 3)

The transition from Bed 2 to the Gonioclymenia Limestone (Bed 3) was not exposed in the trench. It is likely that most or all of the Gonio. subcarinata Zone (UD V-A₂) is locally missing. Bed 3 is up to 65 cm thick and consists of grey to reddish crinoidal limestone (Fig. 4). In thin-sections (Fig. 5b), it is developed as a bioturbated, macrofossil-rich float- packstone with a minor content of small-sized, angular quartz grains. The fauna is dominated by ammonoids (Gonio. speciosa; Fig. 8a), broken, reworked crinoid remains, trilobites and corals. There are small-sized oncolites/ooids, which were probably washed in by storms. Oncolites were previously documented in the region by Wendt (Reference Wendt1988 a, fig. 4) from the B. aculeatus aculeatus Zone of a condensed section 2 km south of the Amelane road pass. As in Bed 2, there is no typical neritic or even euphotic fauna. In contrast, orthoconic cephalopods, ostracods, remains of thin-shelled bivalves, trilobites, gastropods and deep-water, solitary rugose corals are common in thin-section. A bulk of the skeletal elements is fractured and broken. As a special feature there are heterocorals (Fig. 5b, insert). Based on records from the Rhenish Slate Mountains and Tafilalt, Weyer (Reference Weyer1995, Reference Weyer1997) and Piecha (Reference Piecha2004 a) showed that they are typical for dysphotic Famennian cephalopod limestones, but rare in aphotic environments. They occur widely in the upper Famennian of the Tafilalt Platform, including the hypoxic Dasberg Event Beds of the Amessoui Syncline (Hartenfels, Reference Hartenfels2011). Abundant laminated iron crusts enclosed both skeletal grains and early consolidated burrows. Evidence for diagenesis is given by grain margin solution. The micritic matrix consists of compacted pseudopeloids. Deposition took place below the normal wave base but was affected by storm waves, which explains the high percentage of fragmented benthic remains. Microborings of bioclasts, the silt content and the ooids/oncoids are evidence for reworking and an influx from an adjacent up-ramp environment that reached the photic zone. In the wide, undulating outcrop towards the western end of Jebel Ihrs, the top of Bed 3 shows eroded and corroded gonioclymeniids (Fig. 8a) and oncoceratid nautiloids (Fig. 8b). This suggests a next interval of submarine carstification during long-lasting non-deposition due to increased turbulence and regression. This explains the local lack of ammonoids typical for UD V-C (Medioclymenia).

Figure 8. Corroded top surface of the Gonioclymenia Limestone, indicating a long interval of non-deposition and submarine carstification, exposed widely at the western end of Jebel Ihrs. (a) Surface with deeply corroded Gonioclymenia speciosa (Münster, Reference Münster1831); (b) corroded section of a large oncoceratid.

As for Bed 2, the rich conodont fauna of Bed 3 (Figs 6, 9) is dominated by Pa. gracilis gracilis and Neo. communis communis; B. aculeatus aculeatus is moderately common. Slender pseudopolygnathids as well as B. costatus Morphotype 2 continue from below as rare forms; B. costatus Morphotype 1 is also present. A similar association, but with rare Pa. perlobata schindewolfi, Pa. perlobata helmsi, B. stabilis bituberculatus, Ps. primus tafilensis ssp. nov. and Ps. primus aff. primus, with fewer Neo. communis communis and a higher content of B. stabilis vulgaris, was recovered by the dissolution of a limestone slab with a Gonio. subcarinata (Fig. 9). Therefore, both the loose and the in situ sample of the Gonioclymenia Limestone fall in the (higher) B. costatus Subzone.

Figure 9. Conodont record and biofacies of loose slabs with Gonioclymenia or Kalloclymenia from Jebel Ihrs West.

Kalloclymenia Limestone (Bed 4b)

Separated by c. 6 cm deeply weathered marl/shale (Bed 4a, Fig. 4), a second quarried, massive, slightly more reddish limestone (Bed 4b) is 23 cm thick and contains Kalloclymenia sp. Therefore, it is here called Kalloclymenia Limestone. The fauna is dominated by crinoids and ammonoids, but both are mostly broken. In thin-section (Fig. 5c) there are associated ostracods, fragmented bivalves, rare trilobites, rugose deep water corals, heterocorals and burrows. Again, brownish-black, laminated, Frutexites-type structures enclose many skeletal grains, which attests continuing slow sedimentation rates. As in Bed 3, there are some angular, small-sized quartz grains and, extremely rare, oncolites. However, as a significant difference, there are also numerous, irregular, sparite-filled, small-scale fenestral fabrics in the middle part (cf. Tebbutt, Conley & Boyd, Reference Tebbutt, Conley and Boyd1965). Such structures are commonly interpreted as filled biogenic/microbial textures and have previously been described from the Tafilalt (Wendt, Aigner & Neugebauer, Reference Wendt, Aigner and Neugebauer1984). Wolf (Reference Wolf1965) introduced the term ‘open-space structures’ for variously sized cavities in carbonate rocks, filled with calcite and/or internal sediment (Flügel, Reference Flügel2004). The whole bed shows an advanced microsparitization. According to Folk (Reference Folk1959), microsparite refers to a calcite matrix with rather uniform crystal size (5–10 µm) and equal shape. The recrystallization took place during late diagenesis, affected by surface water (Folk, Reference Folk1974; Longman, Reference Longman1977). The Gonioclymenia and Kalloclymenia limestones are separated by an interval of non-deposition (UD V-C), re- and transgression. The microbialithic microfacies of the latter suggests a moderately agitated, slightly shallower deposition within the dysphotic zone.

The conodont fauna of Bed 4b (Figs 6, 9) differs from the Gonioclymenia Limestone by the presence of B. ultimus ultimus Morphotype 1 and Morphotype 2 and by transitional forms between Br. inornata and Br. suprema. There are also several species of two different genera (‘siphonodelloids’), which are related to early Siphonodella. These were called N. Gen. 1 and N. Gen. 2 in Becker et al. (Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c ). They differ from typical S. (Eosiphonodella) in the shape and morphology of their basal cavities. They are left in open nomenclature because of parallel ongoing taxonomic investigations by H. Tragelehn. Rare S. (Eosiphonodella) sp. nov. B (sensu Becker et al. Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c ) could be taken as evidence for the praesulcata Zone, but in the absence of the zonal index species Bed 4b is still kept in the B. ultimus ultimus Zone. Like the microfacies, the conodont biofacies has changed to some extent from Bed 3, now with a strong dominance of Br. inornata. Bispathodus costatus Morphotype 2 is also very common in Bed 4b, followed by B. aculeatus aculeatus and B. spinulicostatus Morphotype 1. Palmatolepis perlobata schindewolfi has disappeared; on a global scale it is not known to have overlapped with B. ultimus ultimus (Kaiser et al. Reference Kaiser, Becker, Spalletta, Steuber and Over2009). This branmehlid (double rowed)–bispathodid assemblage seems to represent a new, moderately shallow (dysphotic) outer shelf conodont biofacies type.

Two loose slabs, one with Kallo. subarmata, one with Kalloclymenia sp., have similar conodont assemblages to Bed 4b (Fig. 9), but with more Pa. gracilis gracilis, B. aculeatus aculeatus and B. ultimus ultimus Morphotype 1. Their palmatolepid–bispathodid biofacies is more typical for pelagic cephalopod limestones (see Sandberg, Reference Sandberg and Barnes1976). Rare B. spinulicostatus Morphotype 3, B. ultimus ultimus Morphotype 2, Neo. fibula sp. nov., Ps. primus tafilensis ssp. nov. and Ps. primus aff. primus represent accessory taxa. Furthermore, N. Gen. 1 div. sp., N. Gen. 2 div. sp. and a yet different ‘siphonodelloid’ (‘aff. N. Gen. 2 sp.’) co-occur with a single specimen of S. (Eosiphonodella) sp. nov. B (sensu Becker et al. Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c ). Therefore, all our Kalloclymenia limestone samples fall in the same interval.

Topmost Famennian (Bed 5b)

Separated by a thin, 5–10 cm thick marl/shale (Bed 5a, Fig. 4), a reddish, lenticular limestone with variable thickness between 5 and 15 cm terminates the local Famennian succession. Bed 5b is a coarse crinoidal packstone with some very fine quartz detritus (Fig. 5d). Skeletal remains derive from ostracods, bivalves, rare trilobites and burrows of uncertain origin. Reddish-brown microstromatolites encrusted skeletal remains, especially crinoids. Constant reworking during storm events is indicated by fragmentation whilst microborings confirm a shallow outer shelf setting. Grain margin solution, particularly between crinoid remains, is common. Similarly to the Kalloclymenia Limestone, Bed 5b shows a distinctive microsparitization. It was deposited on or directly adjacent to a storm-swept crinoidal shoal, but without an influx of skeletal grains from the photic zone. The scarcity of pelagic fauna is distinctive. So far there are no ammonoids and there is only a sparse conodont fauna (Figs 4, 6) with, amongst others, both morphotypes of B. costatus, B. ultimus ultimus Morphotype 2 and, again, N. Gen. 2 div. sp. as well as S. (Eosiphonodella) sp. nov. B (sensu Becker et al. Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c ). The restricted fauna resembles the worsening of environmental conditions recorded in the contemporaneous crinoidal limestone platform of the northern Maider (Becker et al. Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c ). By comparison with sections of the central (Jebel Erfoud; Fig. 10) and eastern Tafilalt Platform (Ouidane Chebbi; Hartenfels, Reference Hartenfels2011) and northern Maider (western Jebel Rheris to Lalla Mimouna), the uppermost Famennian of Jebel Ihrs is extremely condensed and incomplete.

Figure 10. Correlation of the Gonioclymenia Limestone section at Jebel Ihrs West with thicker or strongly condensed and incomplete successions with Gonio. speciosa, along a curved transect through the Tafilalt Platform (see inserted map).

Bispathodus aculeatus aff. aculeatus (Branson & Mehl, Reference Branson and Mehl1934a)

Figure 18s–v

Material . Four specimens from Jebel Ihrs West and Oum el Jerane.

Description . In oral view, this form is elongate, nearly straight, or only slightly bowed laterally. Two or more (up to six) fused side denticles are developed on the right side of the blade in a central position more or less above the basal cavity and not extending to the posterior tip of the blade. The side denticles form a discrete platform-like bulk rather than splitting off from the main blade denticles. The latter are distinctively fused in the range of the basal cavity. Posterior, the denticles stand in close contact and show rounded cusps. Ideally, they are spiky and triangular. Anteriorly, the transition from the carina to the free blade is slightly discontinuous. The high free blade is an extension of the carina; in lateral view, it shows a tendency towards Clydagnathus. The denticles increase successively and reach the highest point just before the anterior margin. The oral profile posterior to the basal cavity is gently convex. The aboral outline is conspicuously straight, but slightly arched downwards behind the basal cavity. The latter is relatively small, symmetrical, and restricted to the central part. Aborally, a small median groove extends from the anterior to the posterior end.

Discussion . In typical B. aculeatus aculeatus, the lateral denticles are connected by transverse ridges with the carina and stand more or less isolated from each other. Ziegler, Sandberg & Austin (Reference Ziegler, Sandberg and Austin1974) pointed out that in some specimens the side denticles split off from the main blade. According to Ziegler, Sandberg & Austin (Reference Ziegler, Sandberg and Austin1974: pl. 2, fig. 1), the re-illustrated lectotype of B. aculeatus aculeatus, selected by Ziegler (Reference Ziegler1962), shows a tendency towards B. aculeatus plumulus (= Clyd. plumulus) in the development of a high anterior free blade. This is also true for B. aculeatus aff. aculeatus. However, the typical plume-like Clydagnathus blade (Rhodes, Austin & Druce, Reference Rhodes, Austin and Druce1969), with denticles which are highest in the posterior part and markedly recurved backwards, are not developed. In Clyd. plumulus, the free blade does not continue the platform carina. Bispathodus aculeatus aff. aculeatus is distinguished from Clyd. tragelehni both by the dense arrangement of the right denticles and the absence of a plume-like free blade (see Hartenfels, Reference Hartenfels2011). In the latter, there is also a break between the carina and anterior free blade. Bispathodus bispathodus differs by having a basal cavity that extends to or close to the posterior tip. Again, the side denticles show a somewhat wider arrangement.

Geographical distribution . Tafilalt.

Stratigraphic range . Gonioclymenia Limestone (B. costatus Subzone).

Bispathodus aculeatus anteposicornis (Scott, Reference Scott1961)

Figure 18g–j

1961 Spathognathodus anteposicornis sp. nov.; Scott, pp. 1224–5, fig. 2H–K.

2011 Bispathodus aculeatus anteposicornis (Scott); Hartenfels, p. 217, pl. 33, fig. 1 [further remarks and synonymy].

2013 Bispathodus aculeatus anteposicornis (Scott); Kononova & Weyer, p. 32, pl. 3, figs 14–15.

Material . 18 specimens from Jebel Ihrs West, Jebel Kfiroun South and Oum el Jerane.

Discussion . One of the illustrated specimens (Fig. 18i, j) is intermediate between B. aculeatus anteposicornis and B. aculeatus aculeatus. A large denticle is present above the anterior margin of the basal cavity on the right side of the blade. In addition, two extremely weak right-side denticles split off from the carina just above the central basal cavity. This specimen is included as a variant within B. aculeatus anteposicornis.

Bispathodus costatus (Branson, Reference Branson and Mehl1934) Morphotype 1 (sensu Ziegler, Sandberg & Austin, Reference Ziegler, Sandberg and Austin1974)

Figure 18ae–af

1974 Bispathodus costatus (Branson) Morphotype 1; Ziegler, Sandberg & Austin, pp. 102–3, pl. 2, fig. 13.

2011 Bispathodus costatus (Branson) Morphotype 1; Hartenfels, p. 219, pl. 34, figs 3–4 [further remarks and synonymy].

2013 Bispathodus costatus (Branson) Morphotype 1; Kononova & Weyer, p. 33, pl. 4, figs 9–10, 12, 14.

Material . 41 specimens from Jebel Ihrs West.

Description . As noted by Hartenfels (Reference Hartenfels2011) and Kononova & Weyer (Reference Kononova and Weyer2014), the holotype of B. bischoffi Rhodes, Austin & Druce, Reference Rhodes, Austin and Druce1969 falls in this morphotype and would be available as a subspecies name. However, because of identical stratigraphic ranges and intergradation we do not support a subspecies distinction of the two costatus morphotypes.

The loose Kalloclymenia sp. sample yielded an aberrant adult specimen of B. costatus (Fig. 18af). The large, rather flat basal cavity extends close to the posterior tip. Thus, the specimen falls in Morphotype 1 sensu Ziegler, Sandberg & Austin (Reference Ziegler, Sandberg and Austin1974). Above the anterior margin of the basal cavity, the main blade is interrupted and offset to the left. The side denticles are connected by weak ridges with the main blade. But curiously, in the anterior part the ornamentation is developed on the left, not on the usual right side.

Bispathodus spinulicostatus (Branson, Reference Branson and Mehl1934), Morphotype 1 (= typical morphotype sensu the holotype)

Figure 18w–y

1934 Spathodus spinulicostatus n. sp., Branson, pp. 305–6, pl. 27, fig. 19

2011 Bispathodus spinulicostatus (Branson) Morphotype 1; Hartenfels, p. 221, fig. 59, pl. 32, figs 5–6 [further remarks and synonymy].

e.p. 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 1; Kononova & Weyer, pp. 35–6, pl. 5, fig. 3 [slightly transitional towards ultimus], pl. 7, fig. 3 [only].

e.p. 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 2; Kononova & Weyer, pp. 35–6, pl. 7, figs 1, 7 [only].

2013 Bispathodus costatus (Branson) Morphotype 2; Kononova & Weyer, pp. 32–3, pl. 5, fig. 6 [only].

e.p. 2014 Bispathodus spinulicostatus (Branson); Malec, fig. 4E, G.

Material . 160 specimens from Jebel Ihrs West and Seheb el Rhassal.

Discussion . Morphotype 1 is characterized by a small basal cavity. It includes several specimens assigned by Kononova & Weyer (Reference Kononova and Weyer2014) either to B. costatus or B. ziegleri.

Bispathodus spinulicostatus (Branson, Reference Branson and Mehl1934) Morphotype 2 (sensu Hartenfels, Reference Hartenfels2011)

Figure 18z

e.p. 1999 Bispathodus ultimus (Bischoff); García-López, Sanz-López & Padro Alonso, fig. 3, pl. 3, fig. 13 [only].

2011 Bispathodus spinulicostatus (Branson) Morphotype 2; Hartenfels, pp. 221–2, fig. 60, pl. 32, figs 5–6 [further remarks and synonymy].

e.p. 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 1; Kononova & Weyer, pp. 35–6, pl. 5, fig. 3 [slightly transitional towards ultimus], pl. 7, figs 2, 5 [only].

e.p. 2013 Bispathodus aff. ziegleri (Rhodes, Austin & Druce); Kononova & Weyer, pp. 35–6, pl. 5, fig. 5 [transitional towards Morphotype 3], pl. 5, fig. 7 [only].

e.p. 2014 Bispathodus spinulicostatus (Branson); Malec, fig. 4F, ?S.

Material . 36 specimens from Jebel Ihrs West.

Description . Morphotype 2 is distinguished from the typical Morphotype 1 by having a large, shallow basal cavity that extends to or close to the posterior tip. The anterior margin of the cavity is more or less rounded and it tapers towards the posterior end of the element. The arrangement of the lateral denticles resembles the typical morphotype. In addition to a row of lateral denticles on the right side of the blade, a row of lateral denticles occurs in the posterior third on the left side. Both rows extend close to the posterior tip. Right and left side denticles are connected by transverse ridges with the main blade and alternate. These ridges are absent or only slightly developed in juveniles, which, however, show the typical proportions of the basal cavity. Bispathodus spinulicostatus Morphotype 2 differs from B. ultimus ultimus Morphotype 1 in the form and arrangement of the ornament, but transitional forms without alternating rows occur.

Discussion . Since Alberti (Reference Alberti1970) and Kaiser (Reference Kaiser2005) did not illustrate their B. spinulicostatus specimens, these first records of the species from the Tafilalt cannot be assigned to the morphotypes established by Hartenfels (Reference Hartenfels2011).

Bispathodus spinulicostatus (Branson, Reference Branson and Mehl1934) Morphotype 3 (new)

Figure 20ae–ah

1979 Bispathodus aff. spinulicostatus (Branson); Kononova, pl. 2, fig. 1.

Material . Six specimens from Jebel Ihrs West.

Description . This new morphotype of B. spinulicostatus shows a row of lateral denticles on the right side of the blade. In some specimens (Fig. 20ae), the minor side denticles anterior to the basal cavity split off (only slightly) from the blade. Towards the posterior end, the denticles are connected with the main blade variably by weak or strong transverse ridges (Fig. 20af–ag); they extend close to the posterior tip. A single transverse ridge or a second row of transverse ridges is developed on the left side of the main blade. They start above the posterior margin of the basal cavity or slightly behind this position and extend close to the posterior tip, too. Their arrangement seems to be irregular, without any specified scheme. If there is more than one transverse ridge, these build a very robust posterior platform. Since their terminal cusps reach beyond the platform, a serrate morphology is generated. In the posterior two-thirds, the denticles of the main blade are commonly fused and transformed into a ridge. The basal cavity is restricted to the central part of the element and does not reach the posterior tip, similar to B. spinulicostatus Morphotype 1. On the left side of the main blade, the basal cavity shows a distinctive bulge, that forms a smooth, platform-like structure. In aboral view, the basal cavity is flat and a weak median groove reaches from the anterior to the posterior tip (Fig. 20ah). Juveniles are not yet known.

Discussion . Within Bispathodus, several species/subspecies show a bulge-like basal cavity on the left side of the main blade. This has been illustrated for B. aculeatus aculeatus (Wang & Yin in Yu, Reference Yu1988: pl. 24, fig. 9), B. aculeatus anteposicornis (Bardasheva et al. Reference Bardasheva, Bardashev, Weddige and Ziegler2004: pl. 13, fig. 4), B. costatus Morphotype 2 (Luppold, Hahn & Korn, Reference Luppold, Hahn and Korn1984: pl. 4, fig. 5; Wang & Yin in Yu Reference Yu1988: pl. 24, fig. 14; García-López, Sanz-López & Padro Alonso, Reference García-López, Sanz-López and Padro Alonso1999: pl. 2, fig. 12) and B. spinulicostatus Morphotype 1 (Corradini, Reference Corradini2003: pl. 1, fig. 10). Similar features are illustrated here for B. aculeatus aculeatus (Fig. 18m), B. costatus Morphotype 2 (Fig. 18ad) and B. spinulicostatus Morphotype 1 (Fig. 18w, x). Bispathodus aff. spinulicostatus sensu Kononova (Reference Kononova1979) agrees with our concept of B. spinulicostatus Morphotype 3. As in our specimen illustrated in Figure 20ae, both characteristic features are developed in her material, an initial platform-bulk as well as a single strong transverse ridge on the left side of the main blade.

Morphotype 3 differs from Morphotype 1 in two features on the left side of the main blade, the distinctive bulge above the basal cavity and the strong transverse ridges, which cause a robust posterior platform. In contrast, Morphotype 2 has a large B. bispathodus-like basal cavity that extends to or close to the posterior tip. Bispathodus ultimus ultimus Morphotype 2 differs in the denticle arrangement on the left side of the main blade, which is much more regular, extending generally above the basal cavity. Bispathodus ultimus ultimus Morphotype 1 is additionally distinguished by its larger basal cavity that reaches to or close to the posterior tip. Both morphotypes of B. costatus differ in the absence of a second row of ornamentation posterior to the basal cavity.

A somewhat similar specimen was illustrated as Ps. dentilineatus by Wang & Yin (in Yu Reference Yu1988: pl. 24, fig. 12) from Sample 29 of the Nanbiancun section IV (Guangxi, south China), which falls in the Lower Carboniferous. However, this specimen develops a right platform with a significant extension to the anterior tip.

Geographic distribution . Tafilalt (Jebel Ihrs) and southern Urals (Sikaza River section 2).

Stratigraphic range . Gonioclymenia and Kalloclymenia limestones, B. costatus Subzone to B. ultimus ultimus Zone with the oldest S. (Eosiphonodella). The specimen of Kononova (Reference Kononova1979) is from the Lytvin horizon and Upper expansa Zone (= B. ultimus ultimus Zone).

?Bispathodus aff. spinulicostatus (Branson, Reference Branson and Mehl1934)

Figure 20v, w

Material . One specimen from Jebel Ihrs West.

Description . The two platforms halves of the adult specimen differ considerably. On the right side, the denticulation consists of regularly arranged, mostly isolated, elongated nodes of the platform margin. They extend much further anteriorly than on the left side. Thereby, the right platform forms a gentle, convex arch that gradually approaches the free blade. The last posterior node is linked with the carina. On the left side, the platform ornament consists of two isolated, widely spaced nodes and a thin ridge connected with the carina. These produce a serrate margin. An additional node is situated above the protruding basal cavity, almost at the same level as the posterior platform nodes. There is also a small node on the opposite right basal cavity extension. The carina is low and extends to the posterior tip. In the anterior part, its denticles are merged into a nodose ridge. The free blade consists of five laterally compressed and fused denticles, showing free tips. An adcarinal groove is restricted on the right side of the platform to the anterior half. In side view, the free blade is highest at mid-length. Towards the posterior tip, the platform is slightly bent downwards. In aboral view, there is a central, broad, constricted and strongly asymmetric basal cavity that tapers towards the posterior end. The lower left side forms a prominent side lobe that, in oral view, protrudes widely below the platform.

Discussion . The specimen may represent a new, rare taxon. It is distinguished from B. spinulicostatus Morphotype 1 by its laterally widened basal cavity with nodes on the upper surface and by the serrate posterior left margin. There are possibly distant relationships with B. ostrovkensis (Dzik, Reference Dzik2006), which type-series seems to include both some Ps. primus primus (his fig. 113A, E) and bispathodids (the holotype, his fig. 113F). In B. muessenbergensis Luppold in Luppold, Hahn & Korn, Reference Luppold, Hahn and Korn1984 the basal cavity is similar to that in B. aff. spinulicostatus, but the very different carina ends in the holotype above it.

Geographic distribution . Tafilalt.

Stratigraphic range . Bispathodus costatus Subzone.

Bispathodus ultimus ultimus (Bischoff, Reference Bischoff1957) Morphotype 1 (sensu Ziegler & Sandberg, Reference Ziegler and Sandberg1984)

Figure 19c–g

1957 Spathognathodus spinulicostatus ultimus Bischoff; Ziegler (in Flügel & Ziegler), pl. 1, figs 10, 16–17.

1959 Spathognathodus spinulicostatus ultimus Bischoff; Helms, pl. 3, figs 6, 9.

e.p. 1962 Spathognathodus costatus spinulicostatus (Branson); Ziegler, pp. 108–9, pl. 14, fig. 11 [only].

1962 Spathognathodus costatus ultimus Bischoff; Ziegler, p. 109, pl. 14, figs 19–20.

1967 Spathognathodus costatus ultimus Bischoff; van Adrichem Boogaert, p. 187, pl. 3, fig. 25.

e.p. 1969 Spathognathodus ziegleri sp. nov.; Rhodes, Austin & Druce, pp. 238–9, pl. 4, fig. 8 [holotype only].

e.p. 1973 Spathognathodus costatus spinulicostatus (Branson); Szulczewski, p. 53, pl. 2, fig. 5 [only].

1974 Bispathodus ultimus (Bischoff); Ziegler, Sandberg & Austin, p. 104, pl. 2, fig. 12.

1975 Bispathodus ultimus (Bischoff); Ziegler, pp. 53–4, Bispathodus, pl. 3, fig. 9.

1984 Bispathodus ultimus (Bischoff) Morphotype 1; Ziegler & Sandberg, pp. 186–7.

2009 Bispathodus ultimus (Bischoff) Morphotype 1; Kaiser, Becker, Spalletta & Steuber, p. 130.

2013 Bispathodus ultimus (Bischoff); Girard et al. fig. 3q.

e.p. 2013 Bispathodus ultimus ultimus (Bischoff); Kononova & Weyer, p. 34, pl. 5, figs 9–11, pl. 6, figs 6–8, pl. 7, figs 11, 14.

e.p. 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 1; Kononova & Weyer, pp. 35–6, pl. 5, fig. 8, pl. 6, figs 1, 4, pl. 7, fig. 6 [only].

? 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 1; Kononova & Weyer, pp. 35–6, pl. 6, figs 2–3, pl. 7, fig. 4 [only, transitional from B. spinulicostatus]

e.p. 2014 Bispathodus ultimus (Bischoff); Malec, fig. 4A–B.

Material . 84 specimens from Jebel Ihrs West.

Discussion : Because of past taxonomic uncertainties and discrepancies, we supply here a new synonymy list for Morphotype 1. The holotype of B. ziegleri Rhodes, Austin & Druce, Reference Rhodes, Austin and Druce1969 (their pl. 4, fig. 8) clearly has a broad basal cavity of bispathodus type, which tapers to the posterior tip. This fact has already been mentioned by Ziegler (Reference Ziegler1975, p. 55: ‘In the majority of specimens, the basal cavity, although aculeatus-like in shape, is distinctly larger than in B. aculeatus. There are few specimens including the holotype that have a bispathodus basal cavity’). Therefore, we re-assign the ziegleri holotype to B. ultimus ultimus Morphotype 1 (see synonymy list above), which corrects the wrong assignment to Morphotype 2 in the synonymy list of Ziegler & Sandberg (Reference Ziegler and Sandberg1984). Since the ultimus holotype represents Morphotype 2, it would be possible to separate both taxa at subspecies level. However, due to the identical stratigraphical range and complete intergradation between both types, we do not support such a taxonomic treatment. Kononova & Weyer (Reference Kononova and Weyer2014) used differences of the posterior ornamentation to separate both forms as species but in fact these are very subtle and there are intermediates that suggest ornament variability within one species. More important are intermediates from B. spinulicostatus Morphotype 2 in which the left posterior ornament consists partly still of nodes, not yet only of transverse ridges, but these do not alternate with the right-side ridges. Such specimens are assigned here with a query to B. ultimus ultimus Morphotype 1.

Bispathodus ziegleri muessenbergensis Luppold, Hahn & Korn, Reference Luppold, Hahn and Korn1984 is characterized by lateral extensions of the basal cavity that bear distinctive small to large denticles. Such forms fall outside the variability range of Moroccan or Thuringian B. ultimus populations and are, therefore, recognized here as a separate species.

Bispathodus ultimus ultimus (Bischoff, Reference Bischoff1957) Morphotype 2 (= typical morphotype sensu the holotype)

Figure 19b

1957 Spathognathodus ultimus sp. nov.; Bischoff, pp. 57–8, pl. 4, figs 24 (holotype)–26.

1959 Spathognathodus cf. costatus (Branson); Voges, p. 299, pl. 34, fig. 47.

e.p. 1962 Spathognathodus costatus spinulicostatus (Branson); Ziegler, pp. 108–9, pl. 14, figs 12–18 [only].

1967 Spathognathodus costatus spinulicostatus (Branson); van Adrichem Boogaert, p. 187, pl. 3, figs 23–4.

e.p. 1967 Spathognathodus costatus spinulicostatus (Branson); Wolska, p. 427, pl. 19, figs 15–16 [only].

e.p. 1969 Spathognathodus ziegleri sp. nov.; Rhodes, Austin & Druce, pp. 238–9, pl. 4, figs ?5, 6–7 [only, non fig. 8 = holotype].

e.p. 1973 Spathognathodus costatus spinulicostatus (Branson); Szulczewski, p. 53, pl. 2, figs 1–2 [only].

1974 Bispathodus ziegleri (Rhodes, Austin & Druce); Ziegler, Sandberg & Austin, p. 104, pl. 2, fig. 16.

1975 Bispathodus ziegleri (Rhodes, Austin & Druce); Ziegler, pp. 55–6, Bispathodus-pl. 3, fig. 10.

1980 ‘Bispathodus cf. B. ultimus’ (Bischoff); van den Boogaard & Schermerhorn, pp. 3–4, pl. 1, figs A–B.

1980 ‘Bispathodus ziegleri’ (Rhodes, Austin & Druce); van den Boogaard & Schermerhorn, p. 7, pl. 1, figs C–D.

e.p. 1984 Bispathodus ultimus (Bischoff) Morphotype 2; Ziegler & Sandberg, pp. 186–7, pl. 2, figs 3–5, 7 [only].

e.p. 1999 Bispathodus ultimus (Bischoff); García-López, Sanz-López & Padro Alonso, fig. 3, pl. 2, fig. 14 [only].

2009 Bispathodus ultimus (Bischoff) Morphotype 2; Kaiser, Becker, Spalletta & Steuber, p. 130.

e.p. 2013 Bispathodus ultimus ultimus (Bischoff); Kononova & Weyer, p. 34, pl. 6, fig. 5 [only].

?e.p. 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 1; Kononova & Weyer, pp. 35–6, pl. 5, fig. 2, pl. 7, fig. 9 [only, still transitional from B. spinulicostatus].

?e.p. 2013 Bispathodus ziegleri (Rhodes, Austin & Druce) Morphotype 2; Kononova & Weyer, pp. 35–6, pl. 5, fig. 12 [only, still transitional from B. spinulicostatus].

e.p. 2014 Bispathodus ultimus (Bischoff); Malec, fig. 4C–D.

2015 Bispathodus ultimus (Bischoff); Mossoni, Carta, Corradini & Spalletta, fig. 7g.

Material . 14 specimens from Jebel Ihrs West.

Discussion . The concept of B. ultimus ultimus in the sense of the holotype, Morphotype 2 sensu Ziegler & Sandberg (Reference Ziegler and Sandberg1984), is based on a centrally situated, B. aculeatus aculeatus-like basal cavity, which does not form a right angle with the main blade. According to Ziegler & Sandberg (Reference Ziegler and Sandberg1984), Spathognathodus costatus ultimus sensu Ziegler (Reference Ziegler1962) does not conform to the holotype of B. ultimus. Its basal cavity is broader and extends to or close to the posterior tip, as in B. ultimus ultimus Morphotype 1. Kaiser (Reference Kaiser2005) and Kaiser et al. (Reference Kaiser, Becker, Spalletta, Steuber and Over2009) added that B. ultimus Morphotype 2 has a small, almost symmetrical basal cavity, whereas Morphotype 1 has a large, asymmetrical one.

Kononova & Weyer (Reference Kononova and Weyer2014) questioned the morphotype concept of Ziegler & Sandberg (Reference Ziegler and Sandberg1984) and did not accept the published synonymies. Based on minor ornament differences, as discussed above, Kononova & Weyer (Reference Kononova and Weyer2014) kept B. ultimus ultimus separate from B. ziegleri. They distinguished two morphotypes of B. ziegleri: Morphotype 1 with large, bispathodus-type and Morphotype 2 with smaller, aculeatus-type basal cavity located in mid-position of the platform. All their figured specimens of B. ziegleri Morphotype 2 are obviously B. spinulicostatus Morphotype 1 (their pl. 7, figs 1, 7) or questionable transitional forms towards B. ultimus ultimus Morphotype 2 (their pl. 5, fig. 12).

A form that is slightly transitional from B. spinulicostatus Morphotype 1 is illustrated in Figure 19a. Its basal cavity is short, more or less restricted to the central platform and the posterior left ridges are very short and denticle-like.

We accept B. ultimus bartzschi Kononova & Weyer, Reference Kononova and Weyer2014 as a valid subspecies of B. ultimus.

Branmehla inornata (Branson & Mehl, Reference Branson and Mehl1934 a)

Figure 19w, x

1934a Spathodus inornatus sp. nov.; Branson & Mehl, p. 185, pl. 17, fig. 23.

2011 Branmehla inornata (Branson & Mehl); Hartenfels, pp. 230–1, pl. 36, figs 4–6 [further remarks and synonymy].

Material . 305 specimens from Jebel Ihrs West, Jebel Kfiroun South, Oum el Jerane, Seheb el Rhassal and Takhbtit West.

Discussion . Nine specimens from the B. ultimus ultimus Zone of Jebel Ihrs West represent transitional forms between Br. inornata and Br. suprema. In contrast to typical Br. inornata, the basal cavity is more elongated but not so strongly asymmetric as in typical Br. suprema. They are also distinguished from Br. suprema by their posterior blade that is only slightly curved side- and downwards. We keep such intermediates as advanced variants of Br. inornata. Previously, similar specimens were noted from the Carnic Alps by Kaiser (Reference Kaiser2005) and Kaiser et al. (Reference Kaiser, Becker, Spalletta, Steuber and Over2009) and from Thuringia by Hartenfels (Reference Hartenfels2011).

Neopolygnathus fibula sp. nov.

Figure 19s–u

? 1966 Polygnathus communis Branson & Mehl; Klapper, p. 21, pl. 6, figs 6, 11.

Types . Holotype GMM B9A.4-41, Figure 19s, t, paratype GMM B9A.4-42, Figure 19u, 16 more paratypes from the type locality.

Derivation of name . From the Latin fibula, due to the cramp shape of the anterior platform ornamentation.

Type locality and level . Gonioclymenia trench at Jebel Ihrs West, loose limestone slab with Kallo. subarmata (Bed 4b), B. ultimus ultimus Zone with the oldest S. (Eosiphonodella), UD VI-A.

Diagnosis . A species of Neopolygnathus with an asymmetric, lanceolate, slightly ovate platform bearing a single, isolated, cramp-shaped node on each side of the anterior platform. The remaining platform is smooth; the curved carina consists of fused denticles and ends just before the posterior tip. The free blade is moderately long (c. 40% of the total length), the basal pit small and positioned under the anterior platform end. Posterior to the basal pit, a large, shallow depression is developed.

Description . The slightly ovate platform of the new species is widest in the anterior third. The outer margin is broadly curved, the inner margin is anteriorly convex, then slightly concave. On both platform sides a single cramp-shaped node is developed, which runs vertical or moderately diagonal towards the carina. The remaining platform is smooth. The carina is separated on each side and over its whole length by a trough, which shallows to the posterior tip. The carina is generally low, but higher in the anterior part, weakly curved, and consists of fused nodes that become very small near the posterior tip. The free blade is shorter than the platform and consists of 9–11 laterally compressed, fused denticles of equal height and with free tips.

In lateral view, the platform is weakly bent downwards towards the posterior end. Aborally, a small, rounded to ovate basal pit lies at the anterior margin of the platform, right at the junction to the free blade. Anteriorly, it extends along the blade as a narrow groove. Immediately posterior to the basal pit, a large, shallow depression is developed, as typical for the genus. From there, a strong and sharp keel increases in height towards the posterior tip.

Discussion . All morphotypes of Neo. communis communis, Neo. communis ozbakensis Weddige, Reference Weddige1984, and Neo. klapperianus (Ashouri, Reference Ashouri2006), which is only known from a juvenile, lack central platform nodes. In our samples there is no intergradation with the much more common Neo. communis communis. All other lower/middle Famennian species have different platform shapes and transverse costae, at least posteriorly. Among the upper/uppermost Famennian taxa, Neo. communis hanensis (Savage, Reference Savage2013) and Neo. communis phaphaensis (Savage, Reference Savage2013) have smooth platforms, Neo. namdipensis (Savage, Reference Savage2013), here elevated to species level, a more leaf-shaped, subsymmetric platform with many marginal nodes reaching the posterior tip. Neopolygnathus renatae Corradini & Spalletta in Corradini, Barca & Spalletta (Reference Corradini, Barca and Spalletta2003) is characterized by a large node or ridge at the margins of the anterior platform, Neo. margaretae Kononova & Weyer, Reference Kononova and Weyer2014 by longer ridges and a very peculiar, guitar-shaped, constricted platform. Neopolygnathus collinsoni (Druce, Reference Druce1969) differs from Neo. fibula sp. nov. in its nodose rostra on the anteriorly strongly constricted platform. In Neo. mugodzaricus (Gagiev, Kononova & Pazukhin, Reference Gagiev, Kononova, Pazukhin and Maslov1987), excluding stratigraphically older material (two morphotypes from Iran; Gholamalian, Reference Gholamalian2005), there are anterior rostra with few nodes and the unconstricted platform is smooth, with very deep adcarinal troughs. In the very different Neo. shangmiaobeiensis Qin, Zhao & Ji, Reference Qin, Zhao and Ji1988 there are two longitudinal ridges on each platform side. In an upper Famennian communis specimen from Wyoming figured in Klapper (Reference Klapper1966) both platforms halves show a node and anteriorly a collar-forming thickening, which gives an ornament reminiscent of our new species. Its adcarinal furrows appear to be deeper.

Neopolygnathus carina s. str., originally from the Upper Tournaisian, is defined by the presence of an oblique, noded ridge on each side of the anterior platform. Neopolygnathus fibula sp. nov. can easily be distinguished by its different, large, cramp-like nodes. Many authors, such as Sandberg (Reference Sandberg and Barnes1976), Sandberg & Ziegler (Reference Sandberg and Ziegler1979), Raven (Reference Raven1983), Weddige (Reference Weddige1984), Dreesen, Sandberg & Ziegler (Reference Dreesen, Sandberg, Ziegler, Bless and Streel1986), Kalvoda & Kukal (Reference Kalvoda and Kukal1987), Matyja (Reference Matyja and Austin1987), Ji & Ziegler (Reference Ji and Ziegler1993), Voronzova (Reference Voronzova1996) and Kaiser et al. (Reference Kaiser, Steuber, Becker and Joachimski2006), have described or listed supposed Famennian Neo. carina. In most cases, there are no illustrations to prove the identification. Ziegler & Sandberg (Reference Ziegler and Sandberg1984) suggested that the species started in the upper Famennian B. stabilis stabilis Zone (= roughly Lower expansa Zone). However, the few figured Famennian (pre-Hangenberg extinction) specimens differ from both Neo. carina s. str. and Neo. fibula sp. nov. in their arrangement and type of the anterior ornament. As pointed out by Carman (Reference Carman1987), the specimens of Sandberg & Ziegler (Reference Sandberg and Ziegler1979) are rejected from Neo. carina because their anterior ridges parallel the carina (cf. Xia & Chen, Reference Xia and Chen2004). They represent a new form, which is additionally characterized by deep and very narrow adcarinal furrows. The even older (rhomboidea Zone) Iranian specimen of Weddige (Reference Weddige1984) possesses a short parallel ridge on the anterior left side, whereas the anterior right side has at least four nodose transverse ridges. The published evidence does not support the view that Neo. carina s. str. occurs in Famennian strata below the Hangenberg Event. Even the oldest post-Hangenberg Event forms, from the Protognathodus kockeli (= Upper praesulcata) Zone of south China (Ji et al. Reference Ji, Wang, Luo, Li and Hu1989) and the Russian Far East (Gagiev & Kononova, Reference Gagiev and Kononova1990), are not typical.

Among the numerous Carboniferous Neopolygnathus taxa there are no similar forms. The serrate, upturned anterior platform margins of Neo. dentatus (Druce, Reference Druce1969) are rostra-like. In Neo. lectus (Kononova in Bushmina & Kononova, Reference Bushmina and Kononova1981) there are also short anterior, longitudinal rostra and the adcarinal furrows fade out on the posterior platform. The rostra of Neo. carmanae Xia & Chen, Reference Xia and Chen2004 form a peculiar collar and there are many platform margin nodes, also near the posterior tip. Numerous nodes on wider anterior platforms characterize Neo. tschatkalicus Nigmadzhanov, Reference Nigmadzhanov1986, Neo. aff. tschatkalicus in Bardasheva et al. (Reference Bardasheva, Bardashev, Weddige and Ziegler2004), Neo. aff. stylensis in Bardasheva et al. (Reference Bardasheva, Bardashev, Weddige and Ziegler2004), and Neo. longanensis (Qie et al. Reference Qie, Zhang, Du, Yang, Ji and Luo2004). Other forms have distinctive longitudinal ridges on the platform, such as Neo. porcatus (Ni, Reference Ni, Feng, Xu, Lin and Yang1984), Neo. communis quadratus (Wang, Reference Wang1989), an invalid junior homonym (Becker, 2012), and Neo. gancaohuensis (Xia & Chen, Reference Xia and Chen2004).

Geographic distribution . Tafilalt and Franconia, possibly Wyoming.

Stratigraphic range . In the Tafilalt, Neo. fibula sp. nov. ranges from the B. costatus Subzone to the top of the B. ultimus ultimus Zone. This agrees with unpublished data from Köstenhof (= Schübelhammer, Franconia, Tragelehn & Hartenfels). The questionable specimen figured in Klapper (Reference Klapper1966) falls in the Lower costatus Zone sensu Ziegler (Reference Ziegler1962, = B. aculeatus aculeatus Zone).

‘Polygnathus’ div. sp. (transitional to N. Gen. 1 sensu Becker et al. Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c )

Figure 21a–h

Discussion . There are 35 specimens from Jebel Ihrs West, Bed 4b (Kalloclymenia Limestone), that are transitional between the Po. inornatus Group (s.l.) and ‘siphonodellids’ with respect to the transformation of a small polygnathid pit into a wider, flat, poorly delimited basal body attachment area as in N. Gen. 1 sensu Becker et al. (Reference Becker, Hartenfels, Aboussalam, Tragelehn, Brice and El Hassani2013c ; cf. Tragelehn, Reference Tragelehn2010, and Fig. 21i–n) or in ‘Po.’ spicatus Branson, Reference Branson and Mehl1934. Such forms will be treated in more detail in a publication by H. Tragelehn.

Pseudopolygnathus primus primus Branson & Mehl, Reference Branson and Mehl1934 b Morphotypes 1–3

Figures 20m–u, 22

1934b Pseudopolygnathus prima sp. nov.; Branson & Mehl, p. 298, pl. 24, figs 24–5 [Morphotype 1].

1934 Pseudopolygnathus irregularis sp. nov.; Branson, p. 316, pl. 26, figs 25–6 [Morphotype 2].

1934 Pseudopolygnathus lobata sp. nov.; Branson, p. 316, pl. 26, figs 1–2 [Morphotype 2 with side lobe].

1934 Pseudopolygnathus unispinosa sp. nov.; Branson, p. 316, pl. 26, fig. 24 [Morphotype unclear].

1934 Pseudopolygnathus corrugata sp. nov.; Branson, p. 317, pl. 26, fig. 23 [Morphotype unclear].

1934 Pseudopolygnathus dentilineata sp. nov.; Branson, p. 317, pl. 26, fig. 22 [Morphotype 2].

1934 Pseudopolygnathus costata sp. nov.; Branson, pp. 317–18, pl. 26, fig. 21 [Morphotype 2].

1934 Pseudopolygnathus varicostata sp. nov.; Branson, p. 318, pl. 26, figs 19–20 [Morphotype 2].

1934 Pseudopolygnathus subrugosa sp. nov.; Branson, pp. 318, pl. 26, fig. 18 [possibly Morphotype 2].

1934 Pseudopolygnathus projecta sp. nov.; Branson, p. 320, pl. 26, figs 10–11 [Morphotype 2].

1934 Pseudopolygnathus inequicostata sp. nov.; Branson, p. 321, pl. 26, fig. 6 [Morphotype unclear].

1934 Pseudopolygnathus crenulata sp. nov.; Branson, p. 321, pl. 26, figs 4–5, 7–8 [Morphotype 2].

1934 Pseudopolygnathus brevimarginata sp. nov.; Branson, p. 322, pl. 26, fig. 3 [Morphotype 2].

1949 Pseudopolygnathus carinata sp. nov.; Youngquist & Patterson, p. 68, pl. 16, fig. 4 [Morphotype 1 with incipient right side lobe].

1949 Pseudopolygnathus constrictiterminata sp. nov.; Thomas, p. 428, pl. 4, fig. 16 [Morphotype unclear].

1949 Pseudopolygnathus cf. Ps. crenulata Branson; Thomas, pl. 4, fig. 18 [Morphotype unclear].

1957 Pseudopolygnathus irregularis Branson; Bischoff, p. 51, pl. 6, figs 12–13 [Morphotype 1 with small side lobe].

1959 Pseudopolygnathus asymmetrica Branson; Hass, pl. 49, fig. 14 [Morphotype unclear].

1959 Pseudopolygnathus prima Branson & Mehl; Hass, pl. 49, fig. 27 [Morphotype unclear].

1959 Pseudopolygnathus dentilineata Branson; Voges, pp. 300–1, fig. 5/II-l [Morphotype 1], fig. 5/II-r [Morphotype 2], pl. 34, figs 49–50 [Morphotype unclear].

1966 Pseudopolygnathus prima Branson & Mehl; Klapper, p. 14, pl. 4, fig. 8 [Morphotype unclear].

1966 Pseudopolygnathus dentilineata Branson; Klapper, pp. 14–15, pl. 5, figs 10–11 [Morphotype 2].

1968 Pseudopolygnathus dentilineata Branson; Canis, p. 546, pl. 73, figs 10, 29 [Morphotype unclear], figs 30–1 [Morphotype 1].

1968 Pseudopolygnathus prima Branson & Mehl; Canis, p. 547, pl. 73, figs 12, 17, 32 [Morphotype 1].

1969 Pseudopolygnathus expansus sp. nov.; Rhodes, Austin & Druce, pp. 209–10, pl. 5, fig. 2 [Morphotype 2 with incipient right side lobe], fig. 4 [trend towards Morphotype 3].

1969 Pseudopolygnathus vogesi sp. nov.; Rhodes, Austin & Druce, pp. 216–17, pl. 5, figs 1, 3, 5–8 [Morphotype 2].

1969 Pseudopolygnathus prima Branson & Mehl; Schönlaub, p. 340, pl. 1, figs 23–4 [Morphotype 1].

1971 Pseudopolygnathus primus Branson & Mehl; Rhodes & Austin, pl. 1, fig. 2 [Morphotype 2].

1971 Pseudopolygnathus dentilineatus Branson; Rhodes & Austin, pl. 2, fig. 20 [Morphotype 2].

1973 Pseudopolygnathus dentilineatus Branson; Szulczewski, pp. 44–5, pl. 5, figs 5, ?6 [Morphotype unclear].

e.p. 1973 Pseudopolygnathus primus Branson & Mehl; Szulczewski, pp. 46–7, pl. 4, fig. 7 [Morphotype unclear], fig. 8 [Morphotype 1] [only].

1973 Pseudopolygnathus dentilineatus Branson; Matthews & Naylor, p. 365, pl. 38, figs 14–15 [?Morphotype 3].

1973 Pseudopolygnathus primus Branson & Mehl; Matthews & Naylor, p. 365, pl. 38, figs 5–6, 21–3 [Morphotype 1].

e.p. 1976 Pseudopolygnathus vogesi Rhodes, Austin & Druce; Dreesen, Dusar & Groessens, pl. 4, figs 1–2, pl. 13, fig. 3 [Morphotype 2] [only].

? 1979 Pseudopolygnathus cf. dentilineatus Branson; Sandberg & Ziegler, pp. 183–4, pl. 3, fig. 19 [non figs 18, 20–21 = relatives of Ps. koestenhofensis/Ps. inordinatus].

e.p. 1981 Pseudopolygnathus primus Branson & Mehl; Klapper (in Ziegler), pp. 401–8, Pseudopolygnathus-pl. 3, fig. 3, pl. 4, figs 1, 6–7, pl. 5, figs 2–3, ?4, 5 [only] [further remarks and synonymy].

1983 Pseudopolygnathus primus Branson & Mehl; Raven, pl. 5, fig. 4 [Morphotype unclear].

e.p. 1985 Pseudopolygnathus aff. dentilineatus Branson; Bartzsch & Weyer, pp. 21–3, pl. 5, figs 1, 4 [Morphotype 1], fig. 6 [Morphotype unclear] [only].

? 1986 Pseudopolygnathus primus Branson & Mehl; Buggisch, Rabien & Hühner, Tab. 1 [no illustration].

1987 Pseudopolygnathus primus Branson & Mehl; Korn & Luppold, pp. 213–14, pl. 2, figs 4, 9, 11 [Morphotype unclear], figs 8, 10 [Morphotype 3].

1987 Pseudopolygnathus primus Branson & Mehl; Kalvoda & Kukal, pl. 5, figs 11–12 [Morphotype unclear].

1989 Pseudopolygnathus primus Branson & Mehl; Ji, Wang & Luo, p. 93, pl. 22, fig. 9 [Morphotype 1].

? 1990 Pseudopolygnathus primus Branson & Mehl; Gagiev & Bogus, fig. 2b [no illustration].

1992 Pseudopolygnathus primus Branson & Mehl; Nemirovskaya, Chermnykh, Kononova & Pazukhin, pl. 3, fig. 2 [Morphotype 2], fig. 3 [Morphotype unclear], fig. 4 [slightly advanced Morphotype 3].

1997 Pseudopolygnathus primus Branson & Mehl; Molloy, Talent & Mawson, pl. 9, figs 4–8 [Morphotype 2].

1999 Pseudopolygnathus dentilineatus Branson; Sanz-López, García-López, Montesinos & Arbizu, pl. 2, fig. 6 [Morphotype unclear].

1999 Pseudopolygnathus primus Branson & Mehl; Sanz-López, García-López, Montesinos & Arbizu, pl. 2, figs 7–8 [Morphotype unclear].

2000 Pseudopolygnathus primus Branson & Mehl; Matyja, Turnau & Żbikowska, fig. 4.1 [Morphotype 3], fig. 4.2 [morphotype unclear].

non 2002 Pseudopolygnathus primus Branson & Mehl; Draganits et al. p. 17, tab. 1, pl. 2, figs 17–19, pl. 3, figs 13, 15 [different subspecies].

e.p. 2003 Pseudopolygnathus primus Branson & Mehl; Corradini, Barca & Spalletta, p. 240, pl. 5, fig. 5 [Morphotype 2] [only].

2004b Pseudopolygnathus primus Branson & Mehl; Piecha, pp. 259–60, pl. 2, figs 1–8 [Morphotype 3, including forms with incipient right side lobe].

2004 Pseudopolygnathus primus Branson & Mehl; Gereke, pl. 2, figs 26–7 [?Morphotype 2].

2007 Pseudopolygnathus dentilineatus Branson; Boncheva et al. p. 343, pl. 3, fig. 6 [Morphotype unclear].

2007 Pseudopolygnathus primus Branson & Mehl; Boncheva et al. p. 343, pl. 3, fig. 11 [Morphotype 2], figs 12–13 [Morphotype unclear].

2008 Pseudopolygnathus primus Branson & Mehl; Habibi, Corradini & Yazdi, p. 774, fig. 4.7 [Morphotype 1].

2009 Pseudopolygnathus primus Branson & Mehl; Gholamalian, Ghorbani & Sajadi, pl. 5, figs 20–1 [Morphotype unclear].

2011 Pseudopolygnathus cf. primus Branson & Mehl; Hartenfels, pp. 317–18, pl. 64, figs 9–12 [Morphotype 3].

non 2011 Pseudopolygnathus cf. dentilineatus Branson; Hartenfels, pp. 310–11, pl. 65, figs 1–3 [Ps. koestenhofensis/Ps. inordinatus].

2013 Pseudopolygnathus primus Branson & Mehl; Mossoni, Corradini & Spalletta, fig. 3.18 [morphotype unclear].

e.p. 2013 Pseudopolygnathus primus Branson & Mehl; Kononova & Weyer, pp. 44–5, pl. 8, figs 8–10 [Morphotype 2] [only, pl. 8, figs 11–12 = ‘siphonodelloids’].

Material . 59 specimens from Jebel Ihrs West, Jebel Kfiroun South, Oum el Jerane and Seheb el Rhassal (all Morphotype 3).

Description. Specimens from the Gonioclymenia Limestone, here assigned to Ps. primus primus Morphotype 3 (Fig. 20m–u), are nearly straight or slightly bowed, with the flexion point at mid-length. The two anterior margins do not face each other; the right platform extends much further anteriorly and gradually approaches the free blade. The left platform ends with a distinctive, rounded shoulder. The free blade and carina consist of low, laterally compressed, and more or less fused denticles with free tips. The platform bears coarse, slightly elongate nodes or transverse ridges that are commonly connected with the carina; the ornamentation is always somewhat irregular. In the posterior third of the platform, the elongated nodes or ridges stretch above the platform and generate a serrate margin. Aborally, a wide, central basal cavity is slightly constricted at both ends and tapers to or close to the posterior tip without forming a keel. A weak median groove reaches from the anterior to the posterior end. In lateral view, the basal cavity is separated from the platform by a distinctive constriction.

Discussion . The synonymy list of Ziegler (Reference Ziegler1981), here updated, suggests a large variability within Ps. primus, especially in the Tournaisian. According to Klapper (in Ziegler, Reference Ziegler1981), there is a complete gradation between forms with a wide basal cavity of the ‘dentilineatus’ type and a smaller, more restricted basal cavity of the ‘primus’ type. Consequently, Ps. dentilineatus was included in the synonymy of Ps. primus by Klapper (in Ziegler, Reference Ziegler1981). Piecha (Reference Piecha2004b ) postulated that the Devonian specimens have a large ‘dentilineatus’ pit, whereas the Carboniferous elements are characterized by a small ‘primus’ pit. This is contradicted by early variants with ‘primus’ type basal cavity from the B. aculeatus aculeatus Subzone of section Kahlleite East (Thuringia), which are illustrated here (Fig. 22a, b).

Figure 22. Upper Famennian Pseudopolygnathus primus primus Branson & Mehl, Reference Branson and Mehl1934 b, early variant of Morphotype 1 (= ‘primus’ Morphotype sensu Klapper, in Ziegler, Reference Ziegler1981) with a small basal cavity converting into a keel, which reaches the posterior tip, Kahlleite East, Thuringia, Bed 36, B. aculeatus aculeatus Zone. (a, b) GMM B9A.4-83; (c, d) GMM B9A.4-84, slightly transitional from Morphotype 3.

As noted by Klapper (in Ziegler, Reference Ziegler1981) and Corradini, Barca & Spalletta (Reference Corradini, Barca and Spalletta2003), Ps. primus primus shows a large variation of platform outline and ornament. Generally, the platform is thick, slightly or strongly asymmetric, and the left margin forms a distinctive projection (e.g. Ps. primus type material, Ps. crenulatus Branson, Reference Branson and Mehl1934, Ps. asymmetricus Branson, Reference Branson and Mehl1934, Ps. sulciferus Branson, Reference Branson and Mehl1934) or at least a rounded corner before it joins the free blade/carina. In typical specimens the right platform extends farther anteriorly. There are elements with either a pointed or more rounded posterior platform end. The ornament varies from strong transversal ridge (running across the whole platform width and partly fused with the carina) to somewhat oblique ridges or large nodes (sometimes elongated) that are restricted to the platform margins.

We recognize three morphotypes, which can be distinguished based on the size and shape of the basal cavity and on the presence or absence of a posterior keel. Morphotype 1 equals the ‘primus’ Morphotype sensu Klapper (in Ziegler, Reference Ziegler1981). The small basal cavity is restricted to the anterior third or the central part of the platform. Posteriorly, a sharp keel reaches the posterior tip (Fig. 22b, cf. Fig. 22d). The ‘dentilineatus’ Morphotype sensu Klapper (in Ziegler, Reference Ziegler1981), Morphotype 2, has a bilobate, laterally more expanded basal cavity than Morphotype 1, which is often more extended posteriorly. Again, a strong keel runs to the posterior end. In Morphotype 3 there is a large, shallow basal cavity, which is slightly constricted and tapers to the posterior tip (Fig. 20n, q). The posterior part of the basal cavity forms a narrow, flat ridge, instead of a keel. All our new Moroccan material belongs to the new Ps. primus primus Morphotype 3, which links Ps. primus primus with the more weakly ornamented Ps. controversus. We are aware that one could place our new morphotype alternatively as a distinctive morphotype within the latter species.

It may be argued to separate other morphological extremes as additional primus morphotypes, for example forms with shortened right platform, resulting in a longer free blade. Forms with an incipient right side lobe are not taxonomically relevant; they developed within Morphotype 1 (Ps. carinatus Youngquist & Patterson, Reference Youngquist and Patterson1949; Ps. irregularis in Bischoff, Reference Bischoff1957), Morphotype 2 (Tournaisian Ps. lobatus Branson, Reference Branson and Mehl1934, and Ps. expansus Rhodes, Austin & Druce, Reference Rhodes, Austin and Druce1969) and Morphotype 3 (see upper Famennian examples in Piecha, Reference Piecha2004 b and Hartenfels, Reference Hartenfels2011: pl. 64, fig. 9), and also in the Tournaisian Ps. constrictiterminatus Thomas, Reference Thomas1949. But there is no evidence for Famennian specimens with a large, anteriorly directed side-lobe or an ‘ear-like process’, as in Ps. foliaceus Branson, Reference Branson and Mehl1934, Ps. apetodus Cooper, Reference Cooper1939, or, especially, in Ps. auritus Youngquist & Patterson, Reference Youngquist and Patterson1949.

Stratigraphic range. As pointed out by Piecha (Reference Piecha2004 b), the main occurrence of the species is in the Lower Carboniferous. However, there is evidence of upper to uppermost Famennian specimens in the literature. Piecha (Reference Piecha2004 b, Refrath 1 Borehole, Rhenish Massif) and Hartenfels (Reference Hartenfels2011, Kahlleite East, Thuringia; Oum el Jerane, Tafilalt) described Morphotype 3 specimens from the B. aculeatus aculeatus Zone (= Middle expansa Zone). This may also apply to the record of Buggisch, Rabien & Hühner (Reference Buggisch, Rabien and Hühner1986, Beuerbach, southern Rhenish Massif, without illustration). Korn & Luppold (Reference Korn and Luppold1987) illustrated Morphotype 3 from the B. costatus Subzone of Effenberg, Rhenish Massif. The two specimens figured by Gholamalian, Ghorbani & Sajadi (Reference Gholamalian, Ghorbani and Sajadi2009) from the B. aculeatus aculeatus to B. ultimus ultimus Zone interval (= roughly Middle/Upper expansa Zone) of Kal-e-Sadar, east-central Iran, and the specimen from Sardinia figured by Mossoni, Corradini & Spalletta (Reference Mossoni, Corradini, Spalletta, Albanesi and Ortega2013) cannot be re-assigned to a morphotype. The possible oldest Morphotype 2 representatives are from the B. aculeatus aculeatus Zone of the Ardennes (Dreesen, Dusar & Groessens, Reference Dreesen, Dusar and Groessens1976; Yves-Gomezée Road Section), B. costatus Subzone of Thuringia (Kononova & Weyer, Reference Kononova and Weyer2014: pl. 8, figs 8, 10), and from the last limestone nodules below the Hangenberg Black Shale at Kahlleite East, Thuringia (Gereke, Reference Gereke2004). Our samples show Tafilalt occurrences of Morphotype 3 in the B. aculeatus aculeatus and B. ultimus ultimus zones.

There are alleged older records without illustrations from the Ps. granulosus Zone of Beringhauser Tunnel, Rhenish Massif (= Upper trachytera Zone; oral comm. of I. Schülcke, noted in Piecha, Reference Piecha2004 b), from the Upper styriacus Zone in Sardinia (Corradini, Barca & Spalletta, Reference Corradini, Barca and Spalletta2003), and from the B. stabilis stabilis (= Lower expansa) Zone of the Russian Far East (Gagiev & Bogus, Reference Gagiev and Bogus1990: Prikolymsky Anticline); these cannot be accepted without revision or further documentation. Older specimens with shorter platforms, a much longer free blade and very large basal cavity, described by Hartenfels (Reference Hartenfels2011) as Ps. cf. dentilineatus from the Tafilalt, Holy Cross Mountains, and Germany (see also specimens of Sandberg & Ziegler, Reference Sandberg and Ziegler1979), are closely related to Ps. koestenhofensis Tragelehn & Hartenfels, Reference Hartenfels2011, and Ps. inordinatus Tragelehn & Hartenfels, Reference Tragelehn and Hartenfels2012.

In summary, upper/uppermost Famennian beds are dominated by Morphotype 3, which ranges from the B. aculeatus aculeatus Zone to the B. ultimus ultimus Zone. However, from the B. aculeatus aculeatus Zone on, there are also isolated occurrences of the two other morphotypes, which dominate after the Hangenberg Event and which range into the Middle Tournaisian.

Pseudopolygnathus primus tafilensis ssp. nov.

Figure 20a–l

e.p. 1985 Pseudopolygnathus aff. dentilineatus Branson; Bartzsch & Weyer, pp. 21–3, pl. 5, figs 2–3, 5 [only].

e.p. 2013 Pseudopolygnathus dentilineatus Branson; Kononova & Weyer, p. 44, pl. 8, ?fig. 4 [broken and encrusted], figs 5–7, pl. 9, figs 1, 3 [only; pl. 9, fig. 2 ?pathological].

Types . Holotype GMM B9A.4-52, Figure 20h–j, paratypes GMM B9A.4-47, Figure 20a, b, GMM B9A.4-48, Figure 20c, GMM B9A.4-49, Figure 20d, e, GMM B9A.4-50, Figure 20f, GMM B9A.4-51, Figure 20g, GMM B9A.4-53, Figure 20k, l.

Derivation of name . After the type region.

Type locality and level . Gonioclymenia trench at Jebel Ihrs West, Bed 3, Gonioclymenia Limestone, B. costatus Subzone, UD V-B.

Diagnosis . A subspecies of Ps. primus with a slender, elongate and weakly curved platform, which lacks a rounded shoulder/corner at the anterior left margin. In medium stages the ornament consists of distinctive, irregularly arranged, partly elongate nodes of platform margins. On the right side, the denticulation extends much farther anteriorly than on the left side and gradually approaches the short free blade. In adult specimens the platform is slightly wider and bears large, closely spaced, partly elongated nodes. Both the right and left sides of the platform meet the blade at about the same position. The central, wide and shallow basal cavity of adults is slightly constricted and tapers to or close to the anterior and posterior tips.

Description . The new subspecies is characterized by its distinctively elongate and weakly curved platform, which is widest near mid-length. In typical specimens, the platform is 4.1–4.7 times as long as wide, but there are specimens with lower (Fig. 20k, l: 3.5) and much higher values (Fig. 20c: 6.0). Both right and left curved specimens are common. In medium stages (Fig. 20a–e) the marginal denticles are isolated, partly elongated and irregularly arranged. The carina comprises a row of discrete nodes, which are somewhat fused at the anterior end. Two adcarinal grooves parallel the carina. The denticulation extends much further anteriorly on the right than on the left side.

In adult forms (Fig. 20f–j) the platform margins bear large, closely spaced, partly elongated nodes. Thus, the ornament becomes less irregular, and the margin serration weakens. Furthermore, the left platform margin is built more anteriorwards. Therefore, the right and left platform sides meet the blade at about the same position. The carina is low and extends to the posterior tip. In the anterior part the nodes are commonly fused to a ridge. Adcarinal grooves are restricted to the anterior two-thirds. Posteriorly, the side nodes are incipiently connected with the carina. In the transition to the free blade, the carina rises slightly; the short free blade is highest in mid-position and consists of four or five laterally compressed, fused denticles with free tips. Throughout ontogeny there is no distinctive or rounded shoulder/corner of the anterior left margin.

In lateral view, the platform is weakly bent downward towards the posterior tip. The central basal cavity is separated from the platform by a constriction. Aboral, in adult forms it is slightly constricted and tapers to or close to the anterior and posterior tips. A weak median groove reaches from the anterior to the posterior end. There is no posterior keel.

Discussion . The new subspecies differs from all three morphotypes of Ps. primus primus in its different platform outline, especially of the left side. This distinction can also be applied to slender forms of Ps. primus primus (e.g. Matyja, Turnau & Żbikowska, Reference Matyja, Turnau and Żbikowska2000, fig. 4.2). Our new form has previously been described from Thuringia as Ps. aff. dentilineatus by Bartzsch & Weyer (Reference Bartzsch and Weyer1985), who recognized two different forms. Their specimens (their pl. 5, figs 1, 4, 6), in which the anterior margins are not directly opposite and with an anterior left platform corner are here re-assigned to Ps. primus primus. Other lanceolate elements (their pl. 5, figs 2–3, 5) show the diagnostic features of Ps. primus tafilensis ssp. nov., which was supported more recently by Kononova & Weyer (Reference Kononova and Weyer2014).

The majority of Famennian pseudopolygnathids have very different platforms and longer free blades (e.g. Bischoff & Ziegler, Reference Bischoff and Ziegler1956; Bouckaert & Groessens, Reference Bouckaert and Groessens1976; Korn & Luppold, Reference Korn and Luppold1987; Hartenfels, Reference Hartenfels2011; Tragelehn & Hartenfels, Reference Hartenfels2011; Mossoni et al. Reference Mossoni, Carta, Corradini and Spalletta2015). Among Carboniferous pseudopolygnathids, the similarly slender Ps. nodosus Wang & Wang, Reference Wang and Wang2005 has a much weaker ornament and different carina. Pseudopolygnathus primus tafilensis ssp. nov. is slightly similar in oral view to Ps. multistriatus (or rather, its younger synonym Ps. lanceolatus Hass, Reference Hass1959). But the latter consistently has a much more restricted basal cavity, especially in large specimens (see distinction of Ps. multistriatus from the ‘dentilineatus’ morphotype of Ps. primus by Klapper in Ziegler, Reference Ziegler1981). Pseudopolygnathus altaicus Kononova, Reference Kononova, Bushmina, Bogush and Kononova1984 records from the Carboniferous at Kozhim (Polar Urals), figured in Nemirovskaya et al. (Reference Nemirovskaya, Chermnykh, Kononova and Pazukhin1992), differs also in the position, shape and morphology of the basal cavity; the basal cavity is situated more anteriorly, not in a central position. The distinction of Ps. primus tafilensis ssp. nov. as an early subspecies is underlined by the fact that no similar Carboniferous specimen was recorded by the various authors who described or named the many Tournaisian primus/dentilineatus variants (see synonym list).

Geographic distribution. Tafilalt, Franconia, Thuringia.

Stratigraphic range . In the Tafilalt Ps. primus tafilensis ssp. nov. ranges from the B. costatus Subzone to the B. ultimus ultimus Zone. In Thuringia, Bartzsch & Weyer (Reference Bartzsch and Weyer1985) illustrated it from nodular interbeds of the Hauptquarzit (B. aculeatus aculeatus Subzone), Kononova & Weyer (Reference Kononova and Weyer2014) from the B. costatus Subzone. Unpublished collections from Köstenhof (= Schübelhammer, Franconia, Tragelehn & Hartenfels, in prep.) include specimens from the middle part of the B. aculeatus aculeatus Zone.

Pseudopolygnathus primus aff. tafilensis ssp. nov.

Figure 20x–z

e.p. 2013 Pseudopolygnathus dentilineatus Branson; Kononova & Weyer, pp. 44, pl. 8, fig. 3 [Morphotype 2] [only].

Material . Four specimens from Jebel Ihrs West.

Discussion . The specimens represent a slightly wider variant of Ps. primus tafilensis sp. nov. with straight platform and without posterior constriction of the basal cavity. The anteriormost node on the right side is separated from the others. This form is somewhat transitional towards the typical subspecies with respect to the presence of an incipient left platform shoulder. In contrast to adult Ps. primus tafilensis ssp. nov., the rounded left side nodes end with the anterior margin of the basal cavity. We include a similar specimen from Thuringia figured by Kononova & Weyer (Reference Kononova and Weyer2014).

Draganits et al. (Reference Draganits, Mawson, Talent and Krystyn2002) illustrated poorly preserved, partly fragmentary pseudopolygnathids from just below and above a supposed Hangenberg Black Shale equivalent of Spiti, NW India, unfortunately without views of the basal cavity. Two of the more complete specimens lack a left platform shoulder, as in Ps. primus tafilensis ssp. nov., but there are only a few left platform nodes. The Himalayan form, therefore, differs from both Ps. primus subspecies recognized here.

Geographic distribution . Tafilalt, Thuringia.

Stratigraphic range . Bispathodus costatus Subzone (Costaclymenia and Gonioclymenia beds at Jebel Ihrs West).

Pseudopolygnathus primus aff. primus Branson & Mehl, Reference Branson and Mehl1934 b

Figure 20ab–ad

Material . Two specimens from Jebel Ihrs West.

Discussion . The elongate specimens differ from typical Ps. primus primus Morphotype 1 in the lack of a distinctive left platform shoulder (Fig. 20ac). The left platform continues anteriorly from the basal cavity area as a very narrow, smooth area and both platform sides meet in same position close to the anterior tip. Therefore, there is only a very short free blade with three fused denticles that are higher than the carina (Fig. 20ab); the highest point of the free blade is at the central or posterior denticle. The main distinction from Ps. primus tafilensis ssp. nov., including the aff. specimens, is the wide but much shorter, strongly constricted basal cavity, which converts into a marked posterior keel.

No similar specimen has been previously described. With respect to the limited material, we keep open nomenclature but leave the option to establish a future second new subspecies or Ps. primus primus morphotype.

Geographic distribution. Tafilalt (Jebel Ihrs West).

Stratigraphic range . Bispathodus costatus Subzone (limestone slab with Gonio. subcarinata) to B. ultimus ultimus Zone (slab with Kallo. subarmata).

Gonioclymenia hoevelensis Wedekind, Reference Wedekind1914

Figure 14a–d

Type . In order to stabilize the nomenclature of the species, the original of Wedekind (Reference Wedekind1914: pl. VI, fig. 2a–b, Göttingen Collection, no. 388-54, re-illustrated in Fig. 14a, b), is here designated as lectotype. Only a part of the original specimen was available for re-examination but it shows the typical, marked ventrolateral spines of an inner whorl, up to c. 35 mm diameter, and strong, paired ribbing. On the subsequent whorl (up to 18 mm whorl height and c. 11.5 mm whorl width), the spines turn into elongated ventrolateral nodes of approximately every second rib and there is a very deep median furrow on the venter. Sutures possess a very shallow, rounded outer flank lobe (second adventitious lobe), a deep, V-shaped, first adventitious mid-flank lobe and a subangular, moderately deep lobe on the umbilical edge. In the second, more complete syntype (Göttingen Collection, no. 588-53, original of pl. V, fig. 7), now paralectotype (Fig. 14c, d), the inner whorls with their distinctive spines are not preserved and there are no sutures. Up to c. 55 mm diameter, each rib pair produces a marginal node. This specimen is more difficult to separate from Gonio. subcarinata, which lacks pronounced spines and strong subumbilical ribbing at small size (cf. Moroccan and Russian representatives of both taxa illustrated in Bogoslovskiy, Reference Bogoslovskiy1981 and Becker et al. Reference Becker, House, Bockwinkel, Ebbighausen and Aboussalam2002).

Leviclymenia ramula sp. nov.

Figures 14g–j, 23

Types . Holotype GMM B6C.42-3.

Derivation of name . From the Latin ramulus = small spike or branch; due to the incipient subdivision of the ventral lobe by a small third adventitious lobe.

Type locality and level . Loose at Jebel Ouaoufilal, Gonioclymenia Limestone (UD V-B).

Diagnosis . Large-sized, moderately evolute (uw/dm = 0.39), strongly compressed (ww/wh = c. 0.50), bicarinate, with gently rounded flanks, ventrolateral edges and shallow ventral furrows until maturity, and with straight, low, rounded flank ribs. Sutures with deep, very narrow ventral lobe, moderately high, asymmetric and pointed ventral saddle subdivided by a small, rounded third adventitious lobe, moderately deep, asymmetrically pointed second A-lobe, high, narrowly rounded outer flank saddle, very deep, asymmetric, V-shaped first adventitious lobe on the mid-flanks, very high, subangular lateral saddle with a concavity of the upper, outer limb, asymmetric, pointed, deep lobe on the inner flanks, and a low saddle subdivided by a wide, shallow lobe on the umbilical wall.

Description . The holotype is still septate at 120 mm diameter, which suggests an original size of up to 200 mm or more. The inner whorls are not preserved. Shell parameters are: preserved maximum diameter (dm) 130 mm, umbilical width 51 mm, whorl height (wh) 48 mm (wh/dm = 0.37), whorl width (ww) c. 25 mm (ww/dm = c. 0.19, extremely discoidal, ww/wh = c. 0.50), whorl expansion rate 2.30–2.35. A typical suture is illustrated in Figure 23. There are nine low ribs on the quarter of a whorl, which are not as wide as the interspaces. The upper side of the specimen was corroded during a long exposure on the sea-floor and settled by numerous cladochonid corals.

Figure 23. Complete outer suture of Leviclymenia ramula sp. nov., holotype GMM B6C.42-3, at 36 mm wh.

Discussion . In terms of shell form and ribbing, the new species resembles Gonio. speciosa, from which it is clearly separated by its additional adventitious lobe that characterizes Leviclymenia Korn & Klug, Reference Korn and Klug2002. The type-species, Levi. levis (Bogoslovskiy, Reference Bogoslovskiy1981) and Levi. kiensis (Bogoslovskiy, Reference Bogoslovskiy1981), are both more evolute (uw/dm = 0.44–0.50 and 0.46–0.48, respectively). There are also suture differences, for example the shape of the saddle at the umbilical seam and of the lobe on the lower flanks.

Leviclymenia was a direct descendant of Gonioclymenia and, therefore, has been included by Korn & Klug (Reference Korn and Klug2002) in the Gonioclymeniidae. The recognition of very shallow ventral furrows in juveniles of Medio. aguelmousensis from both the Maider (Lambidia) and Tafilalt (Bou Tchrafine and Hamar Laghdad East) suggests that Leviclymenia, again, was the ancestor of Medioclymenia, currently the morphologically simplest member of the Sphenoclymeniidae. Bartzsch & Weyer (Reference Bartzsch and Weyer2012) proposed to distinguish the genus by its very small third A-lobes from the younger ‘Spheno.’ brevispina Group with deeper, well-developed A₃, which is followed here. Ventral furrows are also present in ‘Spheno.’ plana Bogoslovskiy, Reference Bogoslovskiy1981, which represents a different genus with Kalloclymenia-type first and second adventitious lobes that may have rooted independently in Leviclymenia. With repect to this taxonomic and phylogenetic complexity it seems better to place all taxa with three A-lobes in a subfamily Sphenoclymeniinae, rather than placing the successive Leviclymenia and Medioclymenia in different families.

Geographic distribution . Restricted to the Tafilalt.

Stratigraphic range . Most likely exposed top of Gonioclymenia Limestone (top UD V-B).