Toweius brusselensis Steurbaut, 2011

(Fig. 19 K-N)

Toweius brusselensis Steurbaut, 2011: figs 15-16; pl. 1, figs 20-22.

DISTRIBUTION. — This species is known from several boreholes (e.g. Knokke, Vlakte van de Raan) and outcrops (e.g. Gobertange, Nederokkerzeel, Vossem) in Belgium, where it ranges from the middle of the Brussel Sand Formation (middle part of Unit B3) up to the basal part of the overlying Lede Sand Formation. In Belgium its range seems to extend from lower middle NP14 to the base of NP15. Some rare small-sized specimens have been identified in the ‘Chaumont-en-Vexin sands‘ and the ‘Glauconie Grossière s.s.’ of the Paris Basin (base NP14). Occurrences outside Europe are scarce and up to now restricted to the Aktulagay section in Kazakhstan (a few specimens in uppermost NP13, Steurbaut 2011).

DISCUSSION

This taxon is represented by relatively small forms (d = c. 5 µm) in the early part of its range (e.g. middle of Unit B 3 at Vossem; Fig. 19M, N). Late forms from the upper part of the Brussel Sand Formation reach up to 8 µm in length (Fig. 19K).