Apparently some beetles were able to track the receding margins
of continental ice sheets at the end of the last glaciation.
Morgan (1989) reconstructed the movements of the water scavenger
beetle Helophorus arcticus from the last glaciation onwards.
With the onset of the Wisconsin glaciation, northern Canadian
populations of this beetle were forced south in eastern North
America. Lowered sea level probably provided suitable habitats
along the exposed continental shelf from Labrador south to New
England. Inland, H. arcticus inhabited the shores of proglacial lakes,
a habitat not currently in existence at these latitudes, but one that
most certainly has been available throughout much of the Quaternary
history of North America. When the Laurentide ice margin
retreated, H. arcticus populations apparently followed it back to its
point of origin in arctic Canada.