Scolopodus quadratus Pander, 1856

Zhen, Yong Yi, Percival, Ian G. & Webby, Barry D., 2003, Early Ordovician Conodonts from Far Western New South Wales, Australia, Records of the Australian Museum 55 (2), pp. 169-220 : 212

Scolopodus quadratus Pander, 1856

Fig. 27A–O

Scolopodus quadratus Pander, 1856: 26 , pl. 2, fig. 6a–d, pl.A, fig. 5d.

Scolopodus costatus Pander, 1856: 26 , pl. 2, fig. 7a–d, pl.A, fig. 5e.

Scolopodus striatus Pander, 1856: 26 , pl. 2, fig. 8a–d, pl. A, fig. 5f.

Scolopodus rex Lindström, 1955: 595 , 596, pl. 3, fig. 32.

Scolopodus rex var. paltodiformis Lindström, 1955: 596 , pl. 3, figs. 33, 34.

Scolopodus quadratus .– Fåhraeus, 1982: 21, pl. 2, figs. 1–14, pl. 3, figs. 1–8, 15.

Scolopodus rex .– Seo et al., 1994, fig. 10.10–10.12.

Scolopodus rex .–Albanesi, in Albanesi et al., 1998: 133, pl. 12, figs. 14–17 (cum syn.).

Scolopodus quadratus .–Zhen et al., in press: pl. 5, figs. 15–21 (cum syn.).

Material. One specimen (Sd) from limestone nodules within shales of the upper Yandaminta Quartzite and 37 specimens (4 Pb, 12 Sa, 12 Sb, 1 Sc, 8 Sd) from the overlying Tabita Formation at Mount Arrowsmith ; two specimens (1 Sa, 1 Sd) from the unnamed dolomitic limestone unit at Koonenberry Gap .

Remarks. Five element types have been recovered from the Tabita Formation, including a scandodiform Pb element with a proclined cusp, four costae on the inner lateral face and a smooth outer lateral face ( Fig. 27A–C ), and four scolopodiform elements: the symmetrical Sa ( Fig. 27D–F ), nearly symmetrical Sb ( Fig. 27G–I ), laterally compressed nearly symmetrical Sc element ( Fig. 27M–O ), and asymmetrical Sd element with slightly twisted cusp ( Fig. 27J–L ). However, the species is highly variable, and there are intermediate morphotypes varying in the number of costae, symmetry, curvature of the cusp, and degree of lateral compression. Scolopodus quadratus also occurs in the slightly older Hensleigh Siltstone of the Lachlan Fold Belt (Zhen et al., in press).

Triangulodus van Wamel, 1974

Type species. Paltodus volchovensis Sergeeva, 1963 .

Figures

Fig. 27. Scolopodus quadratus Pander, 1856: A–C, Pb element, AMF120472, Y4–2, A, outer lateral view, B, outer lateral view of the basal part, showing fine striae, C, inner lateral view; D–F, Sa element, AMF120475, Y4–2, D,F, lateral views, E, close up showing sharp costae and fine striae; G,H, Sb element,AMF120473,Y4–2, G, outer lateral view, H, inner lateral view; I, Sb element,AMF120471, Y4–2, inner lateral view; J–L, Sd element, AMF120474, W5, J, posterior view, K, inner lateral view, L, outer lateral view; M–O, Sc element, AMF120470, TAB1/8.1, M, outer lateral view, N, inner lateral view, O, basal view. Scale bars 100 µm.