16 
Records of the Australian Museum (2009) Vol. 61 
Fig. 8. A-K, Paroistodus proteus (Lindstrom, 1955). (A), M element, CPC39857, WCB705/133, posterior view (IY132-023). B,C, Sb 
element; (B), CPC39858, WCB705/133, inner view (IY132-022); (C), CPC39859, WCB705/133, outer lateral view (IY130-040). D,E, 
Sc element; (£>), CPC39860, 161-166m, outer lateral view (IY130-025); (E), CPC39861, WCB705/133, inner lateral view (IY132-029). 
(F), Sd element, CPC39862, 161-166m, innrt lateral view (IY130-026). G-J, Pb element; (G), CPC39863, WCB705/133, outer lateral 
view (IY117-020); H,I, CPC39864, WCB705/133, (//), basal view (IY117-021), (I), inner lateral view (IY117-022); (7), CPC39865, 
WCB705/133, inner lateral view (IY130-043). (K), Sa element, CPC39866, WCB705/133, lateral view (IY130-41). L-O, gen. et sp. 
indet. A. All from sample WCB705/133. L,M, symmetrical element, CPC39867, (L), basal-posterior view (IY132-024), (M), lateral 
view (IY132-025). N,0, asymmetrical element, CPC39868, (AO, outer lateral view (IY132-028), (O), anterior view (IY132-027). Scale 
bars 100 pm. 
Protopanderodus Lindstrom, 1971 
Type species. Acontiodus rectus Lindstrom, 1955. 
Protopanderodus gradatus Serpagli, 1974 
Fig. 9A-P 
Protopanderodus gradatus Serpagli, 1974: 75, pi. 15, figs 
5a-8b, pi. 26, figs 11-15, pi. 30, figs la-b; text-fig. 17; 
Zhen et al., 2004: 56-57, pi. 5, figs 1-10 ( cum syn .); 
Zhen & Percival, 2006: fig. 9A-C; Zhen et al., in press 
a: fig. 8A-Q. 
Material. 126 specimens from two samples (Table 1). 
Remarks. Protopanderodus gradatus is common in one 
(WCB705/243) of the samples studied from the Emanuel 
Formation. This material is identical with the types described 
from the San Juan Formation (Early Ordovician) of Argentine 
Precordillera (Serpagli, 1974), and those recently docu¬ 
mented from the Honghuayuan Formation of Guizhou, South 
China (Zhen et al., in press a, fig. 8A-Q). An additional 
element (Fig. 9J-P) bearing a more compressed cusp and 
a less extended base with a rounded basal margin has also 
been recognized in the Emanuel material. It also shows 
rather prominent striation in the area immediately anterior 
to the lateral costa, and a weakly developed chevron-shaped 
pattern of striae adjacent to the anterior margin (Fig. 9K, 
O). As these distinctive characters are not observed in the 
other elements of P. gradatus, it is tentatively assigned 
herein to the M position of P. gradatus. Some specimens 
bear rounded holes of about 3-4.5 pm in diameter, presum¬ 
ably representing the boring structure made by an unknown 
organism (Fig. 90, P). 
