A NEW GROENLANDASPIDID ARTHRODIRE (PISCES; PLACODERMI) FROM THE MIDDLE DEVONIAN AZTEC SILTSTONE, SOUTHERN VICTORIA LAND, ANTARCTICA

WA Museum Records and Supplements | Updated 1 decade ago

Abstract - Boomeraspis goujeti gen. et sp. nov is described from isolated trunk-shield plates found in the basal 30 metres of Aztec Siltstone exposed at Alligator Peak in the Boomerang Range of southern Victoria Land. Boomeraspis is characterised by its broad posterior dorsolateral plate (PDL) which has an inflected main lateral line canal and a strongly convex dorsal margin, and the posterior lateral plate (PL) features a strong lateral ridge. These features place Boomeraspis as a primitive member of the family Groenlandaspididae, distinguished from both Tiaraspis and Groenlandaspis by its proportionately longer PDL, strongly ridged and larger PL, and also by the long posterior division of the ventral lamina on the PVL plate.