Elonichthyidae ALDINGER, 1937

Štamberg, Stanislav, 2013, Knowledge Of The Carboniferous And Permian Actinopterygian Fishes Of The Bohemian Massif - 100 Years After Antonín Frič, Acta Musei Nationalis Pragae Series B 69 (3 - 4), pp. 159-182 : 161-163

Family Elonichthyidae ALDINGER, 1937

D i a g n o s i s (after Schindler in Poschmann and Schindler 2004, emended): Skull triangular in lateral aspect. No prominent rostrum. Orbit positioned far anteriorly. Infraorbital sensory canal running far anteriorly on the dermosphenotic. Three pairs of otoliths present, one hemispherical and strongly enlarged. Parasphenoid toothless, without anterior processus ascendens, but with long posterior processus ascendens, processus cultriformis undivided. Skull roof ornamented with knobs, rarely with short striae with ridges of ganoin. Jaws sculptured with long, undivided striae of ganoin with a sharp ridge. Shoulder girdle with long branching striae showing ganoin ridges, striae partly with posterior denticulation. Opercular bones sculptured with small pits. No pineal foramen present. No intertemporal present. Posterior skull roof in one species narrower than anterior skull roof, otherwise of the same width. Dermosphenotic and dermopterotic arranged in line. Dermosphenotic not reaching the nasal. Upper mouth margin formed by premaxilla and maxilla, both of them plus dentary with strong heterodont dentition arranged in 2 – 3 rows. Maxilla with crescent-shaped posterior plate. Antorbital in truly orbital position. Posterior infraorbital posteroventrally enlarged. Ventral accessory operculum present (ventrally or anteroventrally to operculum). More than ten branchiostegal rays present, the first one clearly higher than the remaining ones. Hyomandibular with processus opercularis. Presupracleithrum present. Supracleithrum, with one exception, ventrally stretching beyond operculum. Total body length up to 50 cm. Body slender, with large triangular dorsal and anal fins. Caudal fin heterocercal and deeply forked. Anterior margin of pectoral fin always denticulate, anterior margin of other fins depending on species. Scales sculptured with striae, diagonally divided into a posterodorsal and anteroventral field; striae running posterodorsally parallel to diagonal, anteroventrally parallel to lower scale margin.

I n c l u d e d g e n e r a: Only Elonichthys GIEBEL, 1848 is known from the Bohemian Massif.

“ Elonichthys ” GIEBEL, 1848

T y p e s p e c i e s: Elonichthys germari GIEBEL, 1848 .

D i a g n o s i s (after Gardiner 1963): Body fusiform; fins large with small fulcra anteriorly and lepidotrichia distally bifurcated. Dorsal and anal fins triangular and of much the same size, dorsal fin opposite the space between pelvic and anal fins; pectoral fins with rays joined to their base, and pelvics short based; anal fin triangular, without fringe, similar in shape to pelvics, caudal fin deeply cleft and inequilobate. Skull with well-developed rostrum, oblique suspensorium and medium-sized orbit; operculum larger than suboperculum, with antero-dorsal dermohyal, but no ventral accessory bone in opercular series; suborbitals present, and row of supraorbitals between dermosphenotic and nasal bones. Branchiostegal rays numerous, teeth acutely conical and arranged in two series – inner row of well-spaced, large laniaries and outer row of numerous, closely arranged teeth. Scales rhomboidal, often denticulated posteriorly, large ridge scales in front of median fins. Skull bones ornamented with tuberculations and striae of enamel.

“ Elonichthys ” krejcii ( FRITSCH, 1895)

Text-fig. 2 , figs 2, 3

1895 1895

1991

1991

2006 2006

2010 Acrolepis Krejčii, FR. ; Fritsch, p. 115, pl.128, figs 1–8.

Acrolepis sphaerosideritarum, FR. ; Fritsch, p. 116, pl. 127, figs 1–7.

Watsonichthys krejcii (FRIČ, 1895) ; Štamberg, p. 31, figs 3–5, pls. 1–3.

Watsonichthys sphaerosideritarum (FRIČ, 1895) ; Štamberg, p. 37, figs 6–11, pl. 4.

“ Elonichthys ” krejcii (FRIČ 1895) ; Štamberg, p. 223, fig. 2C “ Elonichthys ” sphaerosideritarum (FRIČ 1895) ; Štamberg, p. 223, fig. 2B

“ Elonichthys ” krejcii (FRIČ, 1895) ; Štamberg, p. 165; figs 9, 10.

H o l o t y p e: Specimen figured by Fritsch (1895) on pl. 128, figs 1–8, deposited in the National Museum, Prague under No. M 1208 (both counterparts) and M 890 (galvanic cast) .

L o c u s t y p i c u s: Malesice, district Plzeň – north, Czech Republic.

S t r a t u m t y p i c u m: Mšec Member, Stephanian B, Upper Carboniferous , Plzeň Basin .

O c c u r r e n c e: A few fragments of the bodies are known as spherosiderite nodules from the locality Malesice in the Plzeň basin. Isolated scales mainly come from several boreholes in the Central and West Bohemian late Paleozoic basins, and the Krkonoše Piedmont Basin ( Štamberg and Zajíc 2008) .

D i a g n o s i s (after Štamberg 1991, emended): Body fusiform not exceeding 130 mm total length. Pectoral fins very long, reaching at least the anterior margin of the pelvic fin. Anal fin base is longer than the dorsal one. Dorsal fin partly opposite the space between the pelvic and anal fins, and partly opposite anal fin base. Small fringing fulcral scales on the leading edge of the pectoral, pelvic, anal and dorsal fins. Maxillary plate is anteroposteriorly elongated, and forms prominent processus ventroposteriorly. Oval operculum narrowing ventrally. Square suboperculum. Numerous branchiostegal rays, first branchiostegal ray ventrally to the suboperculum is two times higher than the rest. Triangular accessory operculum fits tightly in space among operculum, suboperculum and preoperculum. Oval presupracleithrum sits between operculum and supracleithrum.

R e m a r k s: Fritsch (1895) originally described Acrolepis krejcii and Acrolepis sphaerosideritarum from the spherosiderite nodules of the Plzeň Basin. Štamberg (1991) removed these species from the genus Acrolepis particularly for the presence of the accessory operculum and for the similarity of both species with Rhabdolepis eupterygius ( Agassiz, 1833) . Rhabdolepis eupterygius was revised at that time by Heyler (1976) who assigned this species to the genus Watsonichthys . Only after having studied the type specimen of Watsonichthys pectinatus at the Royal Scottish Museum at Edinburgh was I convinced that the maxillary plate of Watsonichthys pectinatus is conspicuously elongated and low, just as different from that of R. eupterygius as from that of “ Elonichthys ” krejcii . The significant difference in the shape of the upper jaw is the primary reason for removing “ E. ” krejcii from Watsonichthys . The configuration of the cheekbones, bones of the opercular apparatus and the dermal bones of the skull roof show close relation to the genus Meisenheimichthys SCHINDLER, 2004 and to the family Elonichthyidae in the sense of Schindler ( Poschmann and Schindler 2004, Schindler 2007). Therefore, I tentatively place “ Elonichthys ” krejcii in the genus “ Elonichthys ” and family Elonichthyidae , in the sense of Schindler ( Poschmann and Schindler 2004). Finally, study of additional material showed that “ Elonichthys ” sphaerosideritarum is a synonym of “ Elonichthys ” krejcii ( Štamberg 2010) . A revision of the genus Elonichthys and its type specimen deposited in the University at Halle is necessary in order to distinguish the principal condition for a correct determination of the actinopterygians from within the range of the Elonichthyidae .

1997 2007 2007 2008

Figures

Text-fig. 2. Reconstruction of some Westphalian and Stephanian actinopterygians. Figs 1 – 5 after Štamberg (1991), Fig. 6 after Westoll (1944). Scale bars represent 20 mm. 1 – Acrolepis gigas (FRIČ, 1877), 2 – “Elonichthys” krejcii (FRITSCH, 1895), figured after the original holotype of Acrolepis sphaerosideritarum FRITSCH, 1895, 3 – “Elonichthys” krejcii (FRITSCH, 1895), figured after the original holotype of Acrolepis krejcii FRITSCH, 1895, 4 – Sphaerolepis kounoviensis FRIČ, 1877, 5 – Sceletophorus biserialis FRITSCH, 1894, 6 – Pyritocephalus sculptus (FRIČ, 1875).