Download Good places to find fossil sponges

SPONGES
What are sponges?
Sponges are ancient animals that mostly live in the sea. They have a very simple body structure
made up of groups, or colonies, of cells. You can find fossil sponges on beaches where most of the
pebbles are made of flint. Look out for flint pebbles with patterns of holes. Quite often you can see
the whole shape of the colony.
The image above shows a piece of flint broken open to reveal the fossil sponge Ventriculites inside.
Although sponges have soft bodies, they fossilise very well because they are made up of tiny pieces
of calcium or silica joined together. When you pick up a piece of flint you are touching the recycled
remains of the silica that the sponge was built from.
Good places to find fossil sponges: pebbly beaches, southern and eastern England
Age of rocks:
145 to 65 million years old (Cretaceous Period)
http://www.nhm.ac.uk/nature-online/earth/fossils/fossil-folklore/themes/decoration06.htm
http://www.nhm.ac.uk/kids-only/earth-space/fantastic-fossils/
Glossary - what does that word mean?
Calcium - the substance that makes our bones and teeth strong. Other animals also use it to make their
hard parts.
Flint - a rock that sometimes contains fossils of animals or plants that lived in the sea. Flint is usually
dark grey or brown but it often occurs in round lumps with a thin, white outer layer.
Silica - a very hard substance. It's what sand is usually made of, and some living things use it in their
hard parts.