Question

Fact sheet on fossil invertebrate group of your choice (/5). Can attach a sketch you made in lab for a bonus mark. PLEASE ATTACH YOUR FACT SHEET AND SKETCH AS THE BACK PAGES OF YOUR SUBMISSION

Chitons

Which group are they most closely related to (cite source)? (/1)

What does the position and region of concentration of Chiton eyes suggest about their importance in anti-predator defense? (/1)

Answer 1

Chitons: They were first studied by Carl Linnaeus in the year 1758. Initially they were known as Cyclobranchians in the 19th century. In 1976, they were grouped as aplacophorans in the subphylum Amphineura in 1876. Later they were known as Polyplacophora (marine molluscs) commonly known as chitons or coat-of-mail shells by de Blainville 1816.

Scien tist have found that chiton (3 inch long) have hundreds of eye-like structures with lenses made of aragonite, a type of rock. These chitons have eyes with lenses which help them to see their predators and defend themselves against being eaten. Chiton eyes made of a calcium carbonate crystal, have been evolved to spot the vision of potential predators.