Mike Tuke’s
ECHINOIDS
www.earth-science-activities.co.uk
Echinoids
Ambulacra and interambulacra
D
An electric bulb placed inside a large modern Echinus shows up the differences between
the ambulacra and interambulacra and shows the outlines of the plates and all the pores as
well.
Shape of echinoids
A P F 10 min
Students are provided with a group of echinoids and they must fill in a table on the basis
of their symmetry, position of mouth and anus and shape of ambulacra.
Evolution of Micraster
A P F 30 min
Students describe the changes in size, depth of anterior groove, height of anus, position
of mouth, size of petals etc between two species of Micraster using either plaster casts
or diagrams.
Earth Science Activities and Demonstrations
