It was speculated that it was the direct ancestor of the Mediterranean Shearwater (now split into Balearic and Yelkouan Shearwaters).
Sibley, Charles Gald & Monroe, Burt L. Jr. (1990): Distribution and taxonomy of the birds of the world.
Shearwater | Short-tailed Shearwater | Shearwater (band) | Sooty Shearwater | Manx Shearwater | Yelkouan Shearwater | Little Shearwater | Great Shearwater | Flesh-footed Shearwater | CFB Shearwater | Balearic Shearwater | Shearwater, Nova Scotia | Shearwater, British Columbia | shearwater | Scarlett's Shearwater | Cory's Shearwater | Cape Verde Shearwater | Audubon's Shearwater | Audubon's shearwater |