Locality
From Hollick (1930) (p. 109)
"Chignik River just below Long Bay, Alaska Peninsula (original No. 54); collected by W. W. Atwood in 1908 (lot 5296)."
Description
From Hollick (1930) (p. 109)
"Trapa? microphylla Lesquereux, U. S. Geol. and Geog. Survey Terr. Bull. 5, ser. 2, p. 369, 1876; The Tertiary flora: U. S. Geol. Survey Terr. Rept., vol. 7, p. 295, pl. 61, figs. 16-17a, 1878." (Lesquereux 1876; 1878)
Remarks
From Hollick (1930) (p. 109)
Detached leaves of this species are included in a number of pieces of matrix from the Chignik Bay region, in one of which they occur massed in layers, in a dark-gray shale, without any other associated vegetation. They vary somewhat in shape and size, as do the type specimens from the Upper Cretaceous (Mesaverde formation) of Wyoming, figured by Lesquereux.
Thus far none of the characteristic fruits of Trapa have been found associated with these leaves in any of our collections; although Heer (1869) (p. 38, pl. 8, figs. 9 - 14) described and figured such fruits from Tertiary rocks at Port Graham, Kenai Peninsula, under the name Trapa borealis, without, however, any accompanying leaves of the genus. As far as I am aware the only record of the leaves and fruit having been found associated together was made by Dawson (1886) (p. 31, pl. 2, figs. 19, 19a, 19b) in connection with specimens from the Upper Cretaceous (?) of Alberta. He referred the leaves (figs. 19, 19a) to Trapa microphylla Lesquereux and the fruit (fig. 19b) to T. borealis Heer. Specimens of leaves were described and figured by Ward (1886; 1887) (p. 554, pl. 49, figs. 2 - 5; p. 64, pl. 28, figs. 2 - 5) from the Eocene (Fort Union formation) of Montana, and by Knowlton (1899; 1900) (p. 661, pl. 77, figs. 3, 4; p. 62, pl. 5, fig. 7) from the Upper Cretaceous (?) of the Yellowstone National Park and the Tertiary (?) Lance formation of Wyoming.
The reference of these leaves to the genus Trapa must be regarded as provisional only. Their original reference to the genus was questioned by Lesquereux: and Knowlton, in his discussion of the specimens from the Yellowstone National Park (Knowlton 1899) says: "These curious but well-marked leaves can not possibly belong to the genus Trapa as we now understand it, but as I am at present absolutely unable to suggest any other affinity I can do nothing but leave their correct determination to be settled by future workers."
Closely similar leaves were described and figured by Newberry (1861) (p. 131, pl. 3, fig. 5) under the name Neuropteris angulata, in connection with which he says: "Scattered pinnules of this plant were found in Cretaceous shales lying upon a bed of lignite north of Oraybe, in the Moqui country [New Mexico]." A comparison of Newberry's figure with figures and specimens of Trapa? microphylla shows them, unquestionably, to be generically identical, even though Newberry classified his specimens as representing a species of the Paleozoic fern genus Neuropteris. Whether or not they should be regarded as specifically identical, however, may still be regarded as an open question."