Eoseira

Name

Eoseira

Rank

Genus

Authors (Pub.)

Wolfe A. P. Edlund M. B.  

Publication

Taxonomy, phylogeny, and paleoecology of Eoseira wilsonii gen. et sp. nov., a Middle Eocene diatom (Bacillariophyceae: Aulacoseiraceae) from lake sediments at Horsefly, British Columbia, Canada [2005/2]

Journal

Canadian Journal of Earth Sciences

Volume

42

Issue

2

Page number

247

Year

2005

Parent Taxon

[Family] Aulacoseiraceae

Fossil Status

valves

Type

Eoseira wilsonii

Diagnosis

Frustules and valves cylindrical, rectangular in girdle view, circular in valve view. Frustules joined valve face to valve face in filaments by broad, flattened marginal spathulate linking spines with apiculate ends. Terminal valves of filaments with broad, flattened lanceolate to broadly ovate separation spines. Spines located circumferentially along the valve face-mantle junction; spines seated on neighboring valves in broad, flat grooves shaped identically to its corresponding separation or linking spine. Areolae on mantle with small round external openings, arranged in straight, parallel pervalvar striae. Single or paired interstriae do not form the linking and separation spines as in the genus Aulacoseira. Rather, spines on Eoseira show no morphogenetic or geometric relation to mantle striae and interstriae. Areolae on mantle and valve face occluded by internal vela. Valves with well developed annular pseudoseptum or Ringleiste. Valves bordered by a smooth, non-areolate collum. Multiple sessile rimoportulae widely scattered on internal mantle wall from the advalvar edge of Ringleiste to the junction of valve face and mantle (Abfallzone). Cingulum comprises numerous open ligulate copulae with fine poroids aligned in pervalvar rows.