Zhen & Nicoll: Canning Basin Serratognathus bilobatus Fauna 
17 
Fig. 9. Protopanderodus gradatus Serpagli, 1974. All from sample WCB705/243. A-C, Sa element; (A), CPC39869, lateral view 
(IY128-010); (5), CPC39870, lateral view (IY128-011); (C), CPC39871, basal view (IY128-008). D-G, Sc element; (D), CPC39872, 
inner lateral view (IY128-001); (E), CPC39873, inner lateral view (IY128-002); (E), CPC39874, basal-inner lateral view (IY128-005); 
(G), CPC39875, upper-inner lateral view (IY128-009). H,I, P element, CPC39876, (H), inner lateral view (IY128-019); (/), basal-outer 
lateral view (IY128-020). J-P, ?M element; J-K, CPC39877, (7), inner lateral view (IY129-037); (K), close-up inner lateral view, showing 
striae near the furrow and chevron-shaped pattern of striae adjacent to anterior margin (IY129-038); L,M, CPC39878, (E), outer lateral 
view (IY129-041); (M), anterior view (IY129-039); N-P, CPC39879, ( N ), inner lateral view (IY129-042); ( O ), close-up inner lateral 
view, showing striae near the furrow and chevron-shaped pattern of striae adjacent to anterior margin (IY129-043); (E), close up showing 
rounded boring hole on the surface (IY 129-044). Scale bars 100 pm unless otherwise indicated. 
Scolopodus Pander, 1856 
Type species. Scolopodus sublaevis Pander, 1856. 
Scolopodus houlianzhaiensis 
An & Xu in An et al 1983 
Fig. 10A-K 
Scolopodus rex houlianzhaiensis An & Xu in An et al. , 1983: 
148, pi. 12, figs 23-27, text-fig. 11.7, 11.8; ?Ding, 1987: 
pi. 6, fig. 23; non Ding et al. in Wang, 1993: 205, pi. 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 (asym¬ 
metrical) 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 Lindstrom, 1955, which is now regarded as 
a junior synonym of Scolopodus striatus Pander, 1856 (see 
Fahraeus, 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 asymmetri¬ 
cal 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, pi. 12, figs 23-25) from 
the Liangjiashan Formation of North China. The Sb element 
