Locality
From Hollick (1930) (p. 106-107)
"Yukon River, north bank, 1 1/2 miles above Williams mine (original No. 36); collected by W. W. Atwood and H. M. Eakin in 1907 (lot 4642)."
Description
From Hollick (1930) (p. 106-107)
"Leaf asymmetric, rounded to the blunt apex on one side, oblique on the opposite side, apparently cordate at the base, 10 centimeters in length by 9.5 centimeters in width across the expanded lower part about 4 centimeters from the base; margin sharply denticulate dentate, the teeth arranged in a double series, the smaller between the larger; nervation pinnate subpalmate, craspedodrome; midrib straight; secondary nerves almost straight, arranged in five subopposite or opposite, subparallel pairs that ascend at angles of 30° to 45° from the midrib, the upper ones subtending the lesser angles, the lowest pair simulating lateral primaries, slightly suprabasilar, branched on the under sides, the basilar branch on the larger side of the leaf with branches similarly arranged; basilar nerves one on each side of the midrib."
Remarks
From Hollick (1930) (p. 106-107)
"No representative of the genus Tilia, so far as I am aware, has been heretofore recorded from any Cretaceous horizon, although six Tertiary species from America and about thirty from the Old World have been described. Tilia dubia (Newberry) Berry (1907) (p. 81, [= Tiliaephyllum dubium Newberry, The flora of the Amboy clays: U. S. Geol. Survey Mon. 26, p. 109, pl. 15, fig. 5, 1895) from New Jersey was described by Newberry as a Cretaceous species; but the deposit in which it was found was subsequetly ascertained to be of late Tertiary or Pleistocene age. Our Alaskan specimen is therefore the first Cretaceous species in the genus to to be recorded, and if the facts are as indicated it represents the oldest known ancestral type of the genus. It is unfortunate that the leaf is somewhat fragmentary, so that a complete description is not possible; but the characters that are preserved are sufficiently wll defined to identify it generically and to differentiate it from other described species."