Microscopic algae-like organisms.

Where in NZ Uncommon.
When Middle Eocene to Pliocene age (45-3 million years old)
Scale 0.07 to 0.25 mm, although most specimens are less than 0.15 mm

What are they?

  • pg 14 - bulboform GNS


    An extinct group of microscopic organisms believed to be related to marine algae.
  • Generally hollow, rounded chambers, made of calcite, and can have complicated surface features such as spines, knobs, and ridges.
  • Can easily be mistaken for simple single-chambered foraminifera or radiolarians.

Used for?

  • Our best bolboform record comes from an Upper Miocene 11 to 8 million year old drill section in the southern Tasman Sea, about 270 km west of central New Zealand, where they are very useful biostratigraphic markers.

See some examples in our image gallery.