USNM 37463 Ginkgo pseudoadiantoides Hollick  


Hollick (1930)

Pl. 28 Fig. 4a




From Hollick (1930) (p. 49-50)

"Yukon River, north bank, about 12 miles below Melozi telegraph station (original No. 3AH11); collected by Arthur Hollick and Sidney Paige in 1903 (lot 3248) (pl. 3, fig. 7b). Yukon River, north bank, about 10 miles below Melozi (original No. 18); collected by W. W. Atwood and H. M. Eakin in 1907 (lot 4633) (pl. 13, figs. 8- 12). Yukon River, north bank, about 1 1/2 miles above Williams mine (original No. 36); collected by W. W. Atwood and H. M. Eakin in 1907 (lot 4642) (pl. 28, fig. 4a)."


Locality Map



From Hollick (1930) (p. 49-50)

"Plate 3, Figure 7b; Plate 13, Figures 8-12; Plate 28, Figure 4a"

"Leaves flabelliform, wedge-shaped, flattened or rounded above, tapering below and gently curved to an elongated, narrow base; margin entire; nervation flabellate, forked."



From Hollick (1930) (p. 49-50)

"More or less variation in form may be noted in the leaves included under this specific name, some of which, such as the one represented by Figure 10 on Plate 13, are so closely similar to certain forms referred to the Tertiary species Ginkgo adiantoides (Unger) Heer (1878) (p. 21, pl. 2, figs. 7 - 10) as to appear almost identical. Comparison between Heer's Figures 8 and 10 and our Figures 10 - 12 on Plate 13 shows this similarity in a striking
manner; and it may be pertinent to infer the possibility that Heer's specimens, at least in part; may have been erroneously identified, inasmuch as their geologic age may be either Cretaceous or Tertiary, according to Kryshtofovich (1918) (pp. 1 - 26) Similar leaves, however, are described and figured by Heer (1883) (p. 57, pl. 87, figs. 9 - 12) from the Tertiary of Greenland, but these all differ more or less from the original Salisburia adiantoides Unger (1845; 1845) (p. Ixxvii; p. 211) of Europe as depicted by Massalongo (1859) (pl. 6, fig. 18; pl. 7, fig. 2; pl. 39, fig. 12) and other authors; and to regard all the forms that have been included in the species by various authors as specifically identical is
about as unsatisfactory as to attempt to differentiate them into distinct species.

It should be recognized, also, that practically no difference can be discerned between certain forms of Ginkgo adiantoides (Unger) Heer, G. laramiensis Ward (see p. 49, pl. 12, figs. 3,4), G. dawsoni Knowlton (1919) (p. 302, 1919 [= Salisburia pusilla Dawson, Roy. Soc. Canada Trans., vol. 11, sec. 4, p. 56, pl. 6, figs. 11-13, 1893 [1894]).) from the Cretaceous of Vancouver Island, and certain of our specimens from Alaska, so that all these specific designations may possess little or no taxonomic significance and be of value merely as convenient names to indicate stratigraphic position."