Diagram highlighting existence of Canis lupus
Tedford, Richard H.; Wang, Xiaoming; Taylor, Beryl E. (modified by <a href="//commons.wikimedia.org/wiki/User:Noles1984~commonswiki" title="User:Noles1984~commonswiki">Noles1984</a>)
2009
Fig. 66 (partim) on p. 175 in: <i>Phylogenetic systematics of the North American fossil Caninae (Carnivora, Canidae).</i> Bulletin of the American Museum of Natural History, no. 325 (available online at <a rel="nofollow" class="external text" href="http://hdl.handle.net/2246/5999">AMNH Library Digital Repository</a>).