36 
J.A. Long 
ridges; Sp, spinal plate; tr.r, transverse ridge on Boomeraspis gen. nov. 
lateral lamina of trunk-shield; 
Type species 
Boomeraspis goujeti sp. nov. 
SYSTEMATICS 
Order Arthrodira Woodward, 1891 
Suborder Phlyctaenioidei Miles, 1973 
Infraorder Phlyctaenii Miles, 1973 
Family Groenlandaspididae Obruchev, 1964 
Diagnosis 
A groenlandaspidid arthrodire having a PDL 
which has an externally ornamented surface 
approximately as long as high, with a prominent 
vertical ridge developed ventral to the point of 
Figure 1 Locality map and stratigraphic section (after Young 1988) showing where the type collection of Boomeraspis 
material was found. 
