Corals and Sponges

Where in NZ Marine mudstone
When Cambrian (542-490 million years ago) to present
Scale A few centimetres to 0.5 m
Fossil coral

Fossil coral

What are they?

  • Corals and sponges are marine aquatic invertebrates from the phyla Cnidaria and Porifera, respectively (there are a few freshwater sponge species).
  • Corals are colonies of many individual polyps which secrete calcium carbonate to form their skeleton.
  • Sponges are much simpler organisms than corals but also produce a calcium carbonate skeleton that can be fossilized.

Used for?

  • Dating sedimentary rock sequences

See some examples in our image gallery.