Orthacanthus gracilis (Giebel, 1848)

Babcock, Loren E., 2024, Replacement names for two species of Orthacanthus Agassiz, 1843 (Chondrichthyes, Xenacanthiformes), and discussion of Giebelodus Whitley, 1940, replacement name for Chilodus Giebel, 1848 (Chondrichthyes, Xenacanthiformes), preoccupied by Chilodus Mueller & Troschel, 1844 (Actinopterygii, Characiformes), ZooKeys 1188, pp. 219-226 : 219

Orthacanthus gracilis (Giebel, 1848)

Fig. 1A

Chilodus gracilis Giebel, 1848: 352-353.

Chilodus gracilis : Giebel 1849: 70, pl. XXIX, fig. 2.

Pleuracanthus sp.: Gocht 1955: pl. VIII, fig. 5.

Orthacanthus -Typ UG: Schneider 1985: 91-92, fig. 2.

Orthacanthus carbonarius (Germar, 1844): Schneider 1988: pl. 1, fig. 4.

Orthacanthus gracilis (Giebel, 1848): Boy and Martens 1991: figs 1, 8.

Orthacanthus gracilis : Hampe 1994: 56-63, figs 1-5.

Orthacanthus gracilis : Hampe 2003: 209-210.

Holotype.

Tooth; Geiseltalmuseum Halle, GTM 1095, previously illustrated by Giebel (1849: pl. XXIX, fig. 2) and Hampe (1994: Fig. 1a-c ).

Type locality.

Slate of the Wettin-Schichten (Carboniferous) from Wettin, north of Halle, Saale area, Saxony-Anhalt, Germany.

Remarks.

The basionym Chilodus gracilis Giebel, 1848 is designated herein as the type species of Chilodus Giebel, 1848. Whitley (1940: 243) proposed Giebelodus as a replacement name for Chilodus Giebel, 1848 (preoccupied by Chilodus Müller & Troschel, 1844), and C. gracilis Giebel, 1848 is thus the type species of Giebelodus . Following Boy and Martens (1991) and Hampe (1994, 2003), Giebelodus gracilis (Giebel, 1848), which is known only from teeth, is referred to the genus Orthacanthus Agassiz, 1843.

Figures

Figure 1. Original 19 th century figures of Carboniferous-age xenacanthiform shark fossils from Saxony-Anhalt, Germany, and Ohio, USA A Orthacanthus gracilis (Giebel, 1848), tooth, holotype (Geiseltalmuseum Halle, GTM 1095), two views; reproduced from Giebel (1849: pl. XXIX, fig. 2 a, b), 7.7 mm long. Wettin-Schichten, Wettin / Saalegebiet, Saxony-Anhalt, Germany B Orthacanthus lintonensis nom. nov., replacement name for Diplodus gracilis Newberry, 1857 a, two teeth, syntypes (repository unknown); reproduced from Newberry (1875 a: pl. LVIII, figs. 3, 3 a), ca 5 and 13 mm long. Upper Freeport Coal, Allegheny Group, Diamond Coal Mine, Linton, Ohio, USA C Orthacanthus adamas nom. nov., replacement name for Orthacanthus gracilis Newberry, 1875 a, dorsal spine, illustration is a composite based on syntypes (Orton Geological Museum, OSU 4467 A, 4467 B); reproduced from Newberry (1875 a, pl. LIX, fig. 7), ca 71 mm long. Upper Freeport Coal, Allegheny Group, Diamond Coal Mine, Linton, Ohio, USA D Orthacanthus carbonarius (Germar, 1844), two teeth, syntypes (repository unknown) of Chilodus tuberosus Giebel, 1848; reproduction of Giebel (1849: pl. XXIX, figs. 1, 1 a, 1 b as), length unknown. Wettin-Loebejun, Saxony-Anhalt, Germany E Orthacanthus carbonarius (Germar, 1844), tooth, syntype (repository unknown) of Lamna carbonaria Germar, 1844; reproduced from Germar (1844: pl. 1, fig. 1), ca 20 mm long. Presumably from Saxony-Anhalt, Germany.