Majanthemophyllum grandifolium Penh.

Plant Fossil Names Registry Number: PFN002114

Act LSID: urn:lsid:plantfossilnames.org:act:2114

Author: D. P. Penhallow

Rank: species

Reference: Penhallow, D. P. (1902): Notes on Cretaceous and Tertiary plants of Canada. – Proceedings and transactions of the Royal Society of Canada, Ser. 2 8(sec. 4): 31–91.

Page of description: 54

Illustrations or figures: fig. 5

Other combinations

Types

Original diagnosis/description

Leaf broadly ovate, about 9.5 cm. wide, and 11.2 cm. long from the base of the sinus to the apex; apex acute; margin entire; obscurely three nerved, the veins about 2–3 mm. distant, the chiefly obscure cross veins either wholly transverse or diagonal.

Emended diagnosis

Stockey, Hoffman and Rothwell (2021: Amer. J. Bot. 108(8): 1419, 1421):
Leaf petiolate, geniculum absent; lamina simple, entire-margined, elliptic to ovate or oblong, 2.9 to >20 cm long; apex acute to slightly rounded, some mucronate; base cuneate to obtuse or cordate. Petiole broad, ~2 cm wide, multi-veined, continuing into lamina as the midrib in basal third. Primary veins parallelodromous, of two orders, diverging from petiole or midrib at acute angles. Submarginal vein present. Transverse veins of one order, opposite percurrent. Higher-order veins mixed opposite/alternate, single diameter, anastomosing, forming rectangular to polygonal areoles; no freely ending veinlets.

Stratigraphy

Paleogene, Paleocene
Paskapoo Formation; late Paleocene; North American Land Mammal Age middle Tiffanian (Ti3); Caryapollenites wodehousei palynostratigraphic zone; magnetostratigraphic zone 26r; ~59 Ma.

[stratigraphy according to Stockey, Hoffman and Rothwell (2021: Amer. J. Bot. 108(8): 1419)]

as Eocene in Penhallow (1902: Proc. & Trans. Roy. Soc. Canada, Ser. 2 8(sec. 4): 54)

Locality

Canada
exposures along both banks of the Blindman River and the northwest bank of the Red Deer River in the area around their confluence southeast of the town of Blackfalds in south-central Alberta, Canada (52°21′18″N, 113°45′00″W)

[type locality according to Stockey, Hoffman and Rothwell (2021: Amer. J. Bot. 108(8): 1419)]

as Red Deer River, N.W.T. in Penhallow (1902: Proc. & Trans. Roy. Soc. Canada, Ser. 2 8(sec. 4): 54)