 Clark is most notable for describing the dinosaur ant ( Nothomyrmecia macrops ) , which is the most primitive living ant in the world and second most primitive when the fossil record is included . The first collection of Nothomyrmecia was made in December 1931 by Amy Crocker who collected specimens of two worker ants , reportedly near the Russell Range from Israelite Bay in Western Australia . Crocker sent the two specimens to Clark at the museum for study ; in 1934 , Clark published a formal description of Nothomyrmecia as a completely new genus of the Myrmeciinae . He did so because the two specimens ( which then became the syntypes ) bore no resemblance to any ant species he knew of , although they did share similar morphological characteristics with the extinct genus Prionomyrmex . This unusual ant remained unknown to scientists , causing intense scientific interest in the early 1950s . Over three decades , however , teams of Australian and American collectors failed to re @-@ find it after they initiated a series of searches . Then , in 1977 , entomologist Robert Taylor and his party of entomologists from Canberra found a solitary worker ant at Poochera , southeast of Ceduna , some 1 @,@ 300 km ( 810 mi ) from the reported site of the 1931 discovery . After 46 years of searching for it , entomologists have dubbed the ant the " Holy Grail " of myrmecology . Such discovery of Nothomyrmecia and its general nature marks it as one of Clark 's most notable achievements . 
