Fig. 4

Placoderm fishes suggesting shallow marine (a-c), possibly marginal marine (d and f), or continental (g-i) faunal exchange between east Gondwana and east Asia. a Skull of the arthrodire Kweichowlepis from the early Emsian Duyun Assemblage of South China (after P’an et al. 1975, pl. 9, 10, fig. 1) re-interpreted as a buchanosteid; b Skull of the Australian Emsian arthrodire Buchanosteus (after Young 1979); c Buchanosteid skull (cf. Errolosteus) with ridged ornament (Wee Jasper, NSW; locality 5, Fig. 1); d and f, Skulls of the bothriolepid antiarch Bothriolepis with a pentagonal preorbital recess; d, Bothriolepis shaokuanensis (Eifelian, Guangdong, China; modified from Chang 1963 and Liu 1973); eB. karawaka, and fB. portalensis from the Aztec sequence (Middle-Late Devonian), southern Victoria Land, Antarctica (from Young 1988); g-i Australian sinolepid antiarch Grenfellaspis branagani (Upper Devonian, Lachlan Fold Belt; locality 9, Fig. 1); g Reconstruction based on the only known articulated specimen (from Young 1999); h and i Articulated specimen in ventral view (h, showing the unique ventral fenestra) and dorsal view (i, skull only). Images not to scale. Abbreviations: f.ven= ventral fenestra, Nu= nuchal plate, orb= orbit (eye socket), orb.f= central opening for eyes, pro= preorbital recess