original description
(of Mytilus (Plicatomytilus) gratacapi Allison & Addicott, 1976 †) Allison R.C., Addicott W.O. (1976). The North Pacific Miocene record of Mytilus (Plicatomytilus), a new subgenus of Bivalvia. <em>United States Geological Survey Professional Paper.</em> 962: 1-22.
page(s): 9, plate 2, figures 1, 3, 4, 6-10; plate 3, figures 1, 3, 5, 7, 8 [details] Available for editors [request]
From editor or global species database
Type locality USA, Alaska, Unga Island, upper part of the Unga Conglomerate member of the Bear Lake Formation [details]