Scolopodus houlianzhaiensis An & Xu

Zhen, Yong Yi & Nicoll, Robert S., 2009, Biogeographic and Biostratigraphic Implications of the Serratognathus bilobatus Fauna (Conodonta) from the Emanuel Formation (Early Ordovician) of the Canning Basin, Western Australia, Records of the Australian Museum 61 (1), pp. 1-30 : 17-22

Scolopodus houlianzhaiensis An & Xu in An et al., 1983

Fig. 10A–K

Scolopodus rex houlianzhaiensis An & Xu in An et al., 1983: 148, pl. 12, figs 23–27, text-fig. 11.7, 11.8;? Ding, 1987: pl. 6, fig. 23; non Ding et al. in Wang, 1993: 205, pl. 14, figs 13–15.

Scolopodus houlianzhaiensis An & Xu. —Zhen et al., in press a: fig. 9G–L.

Material. 19 specimens from three samples ( Table 1).

Remarks. The multicostate Sa (symmetrical) and Sb (asymmetrical) elements of Scolopodus houlianzhaiensis show some resemblance to S. quadratus , but the distinctive Sc element has a strongly compressed cusp and lateral costae restricted to near the anterior margin ( Fig. 10J, K ). An & Xu (in An et al., 1983) considered this species as a subspecies of Scolopodus rex Lindström, 1955 , which is now regarded as a junior synonym of Scolopodus striatus Pander, 1856 (see Fåhraeus, 1982, Zhen et al., 2004; Tolmacheva, 2006).

An & Xu (in An et al., 1983) suggested a bimembrate apparatus including symmetrical and asymmetrical elements. Three morphotypes, representing symmetrical multicostate Sa, asymmetrical multicostate Sb, and strongly asymmetrical Sc elements, can be recognized among our Emanuel material. The Sa element ( Fig. 10A–D ) has a broad anterior face, five or six sharp costae on each side and a costa along the posterior margin, and is identical with the symmetrical element defined by An et al. (1983, pl. 12, figs 23–25) from the Liangjiashan Formation of North China. The Sb element [ Fig. 13 caption continued]… G,H, Sb element, AM F.135823, WHC36, (G), antero-outer lateral view, bearing 10 laminar layers (IY133-013), (H), close up showing denticles along anterior margin of each laminar layer (IY133-014). I,J, Sc element, AM F.135824, WHC36, (I), antero-outer lateral view, bearing 17 laminar layers (IY133-006), (J), posterior view (IY134-001). K, L, Sc element, AM F.135825, THH12, (K), anterior view, bearing 20 laminar layers (IY133-044), (L), posterior view (IY134-029). (N), Sc element, AM F.135826, WHC35, close up showing the small ring-like node representing the initial stage of the element (IY134-014). (O), Sc element, AM F.135817 (same specimen as Fig. 12I ), YTH10, close up showing the rounded pit-like initial stage of the element (IY133-028). Scale bars 100 µm, unless indicated otherwise.

resembles the Sa, but is asymmetrical with a more convex outer lateral face ( Fig. 10E–G ). The Sc element is identical with the asymmetrical element represented by the holotype of the species from the Liangjiashan Formation of North China ( An et al., 1983, pl. 12, fig. 26) with a convex outer lateral face and concave inner lateral face and with several costae (2 to 4) near the anterior margin ( Fig. 10H–K ). Zhen et al. (in press a, fig. 9G–L) reported the occurrence of this species in the Honghuayuan Formation in Guizhou. The Sc element recently illustrated from the Honghuayuan Formation in Guizhou (Zhen et al., in press a, fig. 9G–I) shows a more compressed base, and the Sa element (Zhen et al., in press a, fig. 9J–L) has the base less extended posteriorly, with costae on the lateral face more towards anterior .

Figures

Fig. 10. A–K, Scolopodus houlianzhaiensis An & Xu in An et al., 1983. All from sample 161–166 m. A–D, Sa element; A,B, CPC39880, (A), posterior view (IY130-011), (B), lateral view (IY130-010); C,D, CPC39881, (C), basal view (IY130-009), (D), lateral view (IY130-007). E–G, Sb element, CPC39882, (E), posterior view (IY130-017), (F), inner lateral view (IY130-016), (G), outer lateral view (IY130-018). H–K, Sc element; H,I, CPC39883, (H), posterior view (IY129-028), (I), inner lateral view (IY129-029); J,K, CPC39884, (J), outer lateral view (IY130-019), (K), inner lateral view (IY130-021). L–R, Lissoepikodus nudus Nicoll & Ethington, 2004. L,M, Sa element, CPC39885, WCB705/133, (L), upper view (IY127-002); (M), posterior view (IY127-003). N,O, Pb element; (N), CPC39886, WCB705/133, outer lateral view (IY127-014); (O), CPC39887,WCB705/133, outer lateral view showing weaker costa (IY127-006). P,Q, Sb element; (P), CPC39888, WCB705/243, basal view (IY118-016); (Q), CPC39889, WCB705/133, inner lateral view (IY126-034).(R), Sd element, CPC39890, WCB705/133, basal-inner lateral view (IY126-033). S–U, Nasusgnathus dolonus (An, 1981). All from sample WCB705/133. S,T, Sd element; (S), CPC39891, inner lateral view (IY127-008); (T), CPC39892, outer lateral view (IY127-007). (U), Sb element, CPC39893, WCB705/133, outer lateral view (IY127-005). (V),?Protoprioniodus simplicissimus McTavish, 1973. Sb element, CPC39894,WCB705/243, outer lateral view (IY129-035). (W), gen.et sp. indet. B. Sa element, CPC39895,WCB705/133, posterior view (IY126-036). (X), Paltodus sp. M element, CPC39896, WCB705/133, posterior view (IY126-014). (Y), gen. et sp. indet. A. Symmetrical stout element, CPC39897, WCB705/133, lateral view (IY127-034). Scale bars 100 µm unless otherwise indicated.

Fig. 13. Serratognathus diversus An, 1981. All from the Honghuayuan Formation in Guizhou. Showing size variation; A–E,G,I,K and M are magnified equally. (A), Sb element, AM F.135818, AFI983A, anterior view, bearing six laminar layers (IY133-046). (B), Sb element, AM F.135819, THH10, anterior view, bearing six laminar layers (IY133-038). C,M, Sc element,AM F.135820,YTH5, (C), anterior view, bearing eight laminar layers (IY133-024), (M), posterior view (IY134-019). (D), Sa element,AM F.135821,AFI986, upper-anterior view, bearing eight laminar layers (IY133-050). E,F, Sc element,AMF.135822,YTH4, (E), anterior view, bearing 10 laminar layers (IY133-021), (F), close up showing denticles along anterior margin of each laminar layer (IY133-022). …[continued on facing page]

Fig. 12. Serratognathus diversus An, 1981. All from the Honghuayuan Formation in Guizhou. A–C, Sa element; (A), AM F.135048, THH7, anterobasal view (IY119-004); (B), AM F.135044, THH7, lateral view (IY119-002); (C), AM F.135047, THH10, posterior view (IY119-040). (D), Sb element, AM F.135049, THH7, outer lateral view (IY119014); E–H, broken specimens showing overlapping laminar layers on the surface of breakage. E,F, Sb element, AM F.135815, THH7, (E), postro-lateral view (IY133-035), (F), upper view (IY133-037); G,H, Sc element,AM F.135816, THH9, (G), inner lateral view (IY133-040), (H), close up showing the surface of breakage (IY133-041); (I), Sc element, AM F.135817, YTH10, showing the partition between laminar layers and the fine laminar structure within each laminar layer (IY133-033). Scale bars 100 µm unless otherwise indicated.