Eurycercus longirostris is widely distributed through the whole of the USA and southern Canada, and is present in Churchill, Manitoba and the Yukon Territory. Southernmost populations occur in central Mexico (Bekker et al, 2012).
Eurycercus longirostris was formerly conflated with its congener, E. lamellatus (Müller, 1776). Hann (1982) described E. longirostris from a very limited geographical area in Indiana, USA. Using molecular and morphological methods on material from across the Holarctic, Bekker et al (2012) found E. longirostris to be widespread across North America. This latter study did not find E. lamellatus outside Eurasia, nor E. longirostris outside North America. A subsequent study by Bekker et al (2014) has reported E. longirostris from Wrangel Island and Bering Island, off the coast of the Russian Far East.
This species is found in water bodies of different types, and displays a wide range of temperature preferences (Bekker et al, 2012).
Note Author: Ian Gardiner