USNM 37347 Nilssonia alaskana Hollick  

Notes

Hollick (1930)

Pl. 6 Fig. 6a

 

 

Locality

From Hollick (1930) (p. 45)

"Yukon River, north bank, about 17 miles below Nulato (original No. 33); collected by W. W.
Atwood and H. M. Eakin in 1907 (lot 4639) (pl. 6, fig. 3). Yukon River, north bank, about 5 miles above Louden station [NahochatiltonJ (original No. 22); collected by W. W. Atwood and H. M. Eakin in 1907 (lot 4635) (pl. 6, fig. 4; pl. 7, fig. 2a). Yukon River, north bank, about 5 miles above Louden station [Nahochatilton] (original No. 22A); collected by W. W. Atwood and H. M. Eakin in 1907 (lot 4636) (pl. 7, fig. 9a). Yukon River, north bank, about 6 miles above Nahochatilton (original No. 3AH16); col- lected by Arthur Hollick and Sidney Paige in 1903 (lot 3252) (pl. 6, figs. 5, 6a, 7; pl. 7, fig. 5). Yukon River, north bank, at Fossil Bluff, about 6 miles above Nahochatilton (original No. 2AC238); collected by A. J. Collier and Sidney Paige in 1902 (lot 2962) (pl. 6, figs. 8a, 9; pl. 7, fig. 3). Yukon River, north bank, a short distance above Kaltag (original No. 3AH27); collected by Arthur Hollick and Sidney Paige in 1903 (lot 3266) (pl. 6, fig. 10; pl. 7, fig. 1). Coal mine in Coal Bluff, Herendeen Bay, Alaska Peninsula (original No. 31); collected by W. W. Atwood and H. M. Eakin in 1908 (lot 5185) (pl. 7, figs. 7, 8)."

 

Locality Map

 

Description

From Hollick (1930) (p. 45)

"Plate 6, Figures 3-6a, 7, 8a, 9, 10; Plate 7, Figures 1, 2a, 3a, 5, 7-9a"

"Fronds varying in size, linear oblong or linear obovate, deeply pinnatifid; segments blunt tipped and slightly expanded at the bases, lower ones mostly subtriangular and short, upper ones mostly linear oblong or ligulate, the terminal ones broadest, forming a truncate or broadly emarginate apex; nervation simple, uniform, parallel."

 

Remarks

From Hollick (1930) (p. 45)

"A considerable diversity of forms are included in this species, and possibly more than one species may be represented; but the probabilities appear to be that the specimens merely represent fragments of different parts of the fronds, or fronds from different parts of the plants, or of different stages of growth and age. Typical basal parts are shown in Figures 4 and 10 on Plate 6, and typical apical parts in Figures 3a and 9a on Plate 7.

Certain of the specimens, such as the one represented by Figure 3 on Plate 6, bear a striking resemblance to Nilssonia californica (Fontaine) Fontaine (1905) (p. 252, pl. 67, fig. 7 [= Pterophyllum californicum Fontaine, in Diller, J. S., and Stanton, T. W., Geol. Soc. America Bull., vol. 5, p, 450, 1894]) from the Shasta series of California; and possibly as large a collection of material from that horizon as we have from Alaska might prove them all to belong to one and the same species. Under existing circumstances, however, it seems advisable merely to note the resemblance.

More or less of a superficial resemblance may also be noted to Pterrophyllum concinnum Heer (1874) (p. 68, pl. 14, figs. 15 - 20; pl. 15, figs. 11, 5b) and Pterophyllum lepidum Heer (1874) (pl. 16, figs. 1, 2, 3b) from the Kome beds of Greenland; but the nervation of our specimens, wherever it can be discerned, is clearly that of Nilssonia, and the foliar segments subtend more acute angles with the rachis than those of either of the species of Pterophyllum mentioned."