Three incomplete specimens of a large lobopod, Hadranax augustus gen. ct sp
. nov. are described from the exceptionally preserved Sirius Passet fauna (
Buen Formation, Lower Cambrian, North Greenland). Its overall appearance an
d size are similar to those of Xenusion auerswaldi Pompeckj from the Baltic
, but H. augustus differs in its possession of four poorly defined dorsal n
odes in each row rather than two, and in the probable possession of a pair
of long, branched frontal appendages. The new specimens further demonstrate
that the lobopods were a widespread and diverse Cambrian group. The presen
ce of a four-noded xenusiid refutes the hypothesis that lobopods were direc
tly derived from tetraradial nemathelminthes and shows that both node numbe
r and form were fairly flexible, although their primary function remains un
clear. The probable presence of a pair of long branched frontal appendages
in H, augustus removes one of the major reasons for considering Xenusion to
be a basal lobopod, and adds further to the characters that unite Anomaloc
aris-like taxa to the lobopods.