HdV-A

Taxonomical Group

Algae

Type description

Van Geel 1976: Zygospores quadrate, measuring (31-) 34-42 (-44) µm each way, with sides normally concave. In some zygospores the sides may be observed to be straight or even convex, but this does not seem to be the original condition. The retuse angles (the former points of attachment of the vegetative cells) are (6-) 8-10 (-11) µm in diameter and give some indication of the width of the vegetative cells which did not fossilise. The depth of the depression in each angle varies from 2.4-5 µm. The zygospore walls are densely covered with small pits (0.4 µm in diameter) over their whole surface. Some of the zygospores observed seemed to have furrows, but these could be artificial contraction ridges of the chitinous wall resulting from the preparatory treatment for pollen-sampling.

Records

First publication

van Geel B (1976) Fossil spores of Zygnemataceae in ditches of prehistoric settlement in Hoogkarspel (The Netherlands). Rev. Palaeobot. Palynol. 22:337-344.