Learning activity: Burgess Shale classification key

When paleontologists examine animal fossils they must determine which animal phyla they belong to. Since fossils are not found with labels attached, different techniques are used to help with identification. One such method is a dichotomous key, which simplifies the identification of an unknown organism. The key consists of a series of two mutually exclusive statements that describe characteristics of various organisms. At each step the user determines which statement is correct and is led to the next step in the dichotomous key. The last step ends with the name of the organism.

If you were trying to identify a Tiger, a Gray Wolf, a King Cobra, and a Bald Eagle, the key might read as follows:

1. a) Animal is covered in feathers..................................................................Bald Eagle
    b) Animal is not covered in feathers................................................................go to 2

2. a) Animal has long narrow body covered in scales.......................................King Cobra
    b) Animal is covered in fur..............................................................................go to 3

3. a) Animal has black and orange stripes...............................................................Tiger
    b) Animal has fur which is not striped black and orange.................................Gray Wolf

Your task is to create a dichotomous key for six of the following organisms (the list contains animals from ten different phyla). Clicking on their names will lead you to information and pictures to help with the creation of your key: Anomalocaris, Canadia, Choia, Ctenorhabdotus, Echmatocrinus, Hallucigenia, Micromitra, Nectocaris, Olenoides, Opabinia, Pikaia.


Bethany Kempster

© 2011, Royal Ontario Museum. All Rights Reserved.

Teachers' Centre Home Page | Find Learning Resources & Lesson Plans