The S elements display considerable variation, but all have a tall distinct, gently tapering cusp and a denticulated
White and O'Connell (1982:112) suggested that the most elegant points with finely serrated or denticulated
margins are a post-contact phenomenon.
A number of new taxa, apparatuses with denticulated
processes, such as Yangtzeplacognathus and Eoplacognathus, and several simple-cone conodonts (Dapsilodus, Panderodus, Oslodus, Costiconus, Walliserodus) appeared in this interval (Fig.
Therefore, the specimens above briefly described are tentatively attributed to the order 'Perleidiformes' (sensu Berg, 1937) based on the following characters: body outline fusiform; gape commonly moderate; snout with nasals searated by a large (post)rostral; almost vertical preopercular with an expanded dorsal region; scales deeper than long in the anterior portion of the flank, with the posterior borders often denticulated
; rays of dorsal and anal equal in number to radials; caudal fin heterocercal with several epaxial rays.
serratomarginata because the valves are elongated and serrated (denticulated
) (see arrow, Fig.
anulatus in that its epithelium of the dorsal papillae is papillated, but differs in that it lacks an anal gland and has denticulated
rachidian and lateral teeth.
There are nevertheless several important differences, which also suggest that the jaw apparatus of Kajoprion belongs to labidognath type: (1) symmetrical right and left MII with the ramus and denticulated
shank, (2) presence of a prominent inner wing in the left MI, (3) presence of the subtriangular outer wing in the left MI, and the ramus and bight in the right MI, suggesting the existence of the basal plate, and (4) myocoele openings that are slightly enclosed (Figs 1, 2).
Notosetae in anterior and median regions are homogomph spinigers with blades short to long, finely denticulated (Fig.
Infracicular heterogomph spinigers with long blades, finely denticulated (Fig.