NAME Pluricellaesporites beaufortensis
AGE Late Paleocene - Early to Middle Eocene.   AGE span: 58.7...40.4 mya
K&J CLASSIFICATION (2000) Fungi Imperfecti, Phragmosporae.
FIGURE(S)
Image of
Pl.35fig.13.jpg
FIGURE REFERENCE Parsons MG, Norris G. 1999. Paleogene fungi from the Caribou Hills, Mackenzie Delta, northern Canada; Palaeontographica, Abt. B, v. 250, p. 77-167.
SPECIES, AUTHORITY P. beaufortensis Parsons & Norris 1999, p. 140, pl 7, fig. 16.
LOCATION Caribou Hills, Mackenzie River delta, northern Canada.
ORIG DESCRIPTION* Monoporate fungal spores with a distinctly granular surface inside a smooth, thin-walled perisporium, tetracellate (rarely dicellate or tricellate), narrowly elliptical in outline, with a slight tapering towards the porate end. Rarely, the dicellate specimens have an oval to broadly elliptical shape. Often a short "stalk" - a hilum or pedicel - extends from the pore.

The loose fitting perisporium generally forms a distinct layer clearly separated from the inner spore wall. The spores often occur in clusters with two to more than eight spores being observed to a cluster. Very few specimens are encountered with two or three cells, but dicellate and tricellate spores do occur in groups with the more typical tetracellate spores. In the dicellate spores the median septum divides the spore in half. In the tricellate specimens the median septum divides the spore in half and the second septum divides one of those halves [mostly the distal one], while the other half is undivided. The spacing of the septa in the tricellate and some of the dicellate spores is approximately the same as that in the tetracellate forms, with gaps where the second and/or third septum would be, suggesting that occasionally one or two septa can be lost or fail to develop.

Dimensions, based on thirty-one specimens: total length of spore 25-36 µm, length excluding stalk and perisporium 19-36 µm; total width 11-17 µm, width excluding perisporium: 9-17 µm.
COMMENTS* This species is placed in the genus Pluricellaesporites which encompasses multicellate species with cells of roughly equal size and a single aperture. Although the species can be dicellate, it is typically tetracellate. Species of the genus Brachysporisporites show a gradation in cell size, with markedly larger distal cells.

The combination of a granular surface, prominent perisporium, and "stalk" distinguishes P. beaufortensis from other tetracellate species of Pluricellaesporites. P. beaufortensis is similar to P. apiculatus Kalgutkar 1993 which is tetracellate and may have a small hilum. It differs from the latter species in being prominently granulose with a conspicuous perisporium. As well, the holotype of P. apiculatus has a more uniform width:length ratio throughout the length of the spore, whereas P. beaufortensis is noticeably broadened at the median septum. Brachysporisporites infacetus Kalgutkar (1997) is similar in shape to P. beaufortensis and also has a hilum, but it is more strongly sculptured, large (42-55 x 16-21 µm), and lacks a perisporium.

Named for the Beaufort Sea.
PUBLICATION REFERENCE Parsons MG, Norris G. 1999. Paleogene fungi from the Caribou Hills, Mackenzie Delta, northern Canada; Palaeontographica, Abt. B, v. 250, p. 77-167.
K&J REMARKS
TYPE
ALL NAMES (Including synonyms) Pluricellaesporites beaufortensis
SERIAL NUMBER 1362
PUBLIC COMMENTS
 *For source, see Publication Reference.