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rough part of head shield extends forwardsplate at base D spine large & wideusually skin fold between rear nostrilstop jaw: side front bone concaveroof mouth - 2 pair tooth patches
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head shield: non-granular at front, + narrow deep central grooveroof mouth: 4 tooth patches: rear pair oval
rear edge 1st 2 gill arches - with rakersfemale: pads on pelvic basesgill opening wide, membrane with 5 rays -
head shield non-granular at front, groove wide & shallow
2 front nape plates v large, square/pentagonal
occipital process – short, round, wide at base, rear edge convexroof mouth - 2 pairs large tooth patches with molar teeth, side patches triangular
rear edge 1st 2 gill arches - no rakers
gill opening wide -
head shield rough at front, with narrow grooveroof mouth - 1 pair patches molar teethgill opening: side only, membrane below fused to throat
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head shield non-granular at front, groove wide & shallow
2 front nape plates small, form semilunar structure
occipital process - triangular, long and wide, rear edge concaveroof mouth - 2 pairs tooth patches with pointed teeth, side patches triangularrear edge 1st 2 gill arches - no rakersgill opening wide