An oxymoron? Perhaps, but 500 million years ago, such a creature roamed the vast seas. That was before the dinosaurs and concurrent with the Cambrian explosion. Scientists who put the fossil parts together described the giant shrimp this way:

. . . this underwater predator had a segmented body, a pair of claws and a circular mouth with several layers of overlapping teeth. Its distinguishing feature was a hard carapace that jutted out from its head, the function of which remains something of a mystery since it did not serve as a protective covering for its flesh. . . . With eyes to see and teeth to shred its prey, it would have dominated the food chain in a period when all animal life was underwater.

By “giant,” researchers mean perhaps twice the size of today’s average shrimp.

Globe Life, a Canadian online news source, has the story and illustration: New animal discovered by Canadian researcher. Well, granted the animal is not exactly “new,” the story of the discovery is intriguing from a science educator’s point of view. It amounts to one long puzzle completion exercise.

The fossil remains were found in the famous Burgess Shale region in the Western Canadian Rockies — at different periods in history, by different paleontologists, sent to different museums. However, one graduate student has put the pieces together and deduced the animal’s structure. Paleontologists explain what the giant shrimp tells us today:

. . . The discovery is important to . . . understanding of the development of arthropods, the group of animals with jointed legs that includes crustaceans, spiders and other insects. The segmented body of the hurdia, for example, is the feature that would have eventually developed into the arthropods’ limbs. Both during the Cambrian period and today, arthropods represent the biggest group of animals.

How to Turn This News Event into an Inquiry-Based, Standards-Related Science Lesson

Middle school students often have a good knowledge base regarding dinosaurs, but what do they know about the other life forms prior to that time on earth? The National Science Education Standards for life science suggest middle school students acquire knowledge of structure and function in living systems as well as diversity and adaptations of organisms. Concurrently students are expected to be developing their understanding about scientific inquiry. This story presents a wonderful opportunity to attend to these standards.

Show students the illustration. Ask, “What the heck is that? How big do you think it is? How can you tell?” You can’t, thus the need for inclusion of some kind of scale with illustrations. Alternatively, make copies of the illustration and cut them up into parts and pieces. Include some extraneous, irrelevant pieces. Have small groups of students piece it together, then share their product. How did they go about the process? How did they decide what is important and what is not?

Give them some more information. Tell them this creature is a crustacean and offer a little information about the group Arthropoda, such as — They have hard, exterior exoskeletons like a lobster or crayfish. They have segmented bodies, like an earth worm. Allow students to revise their product.

Share the story with students. Discuss the process: How long have scientists been working on this puzzle? How many different scientists contributed, from which countries? This underscores two aspects of the nature of science: (1) It is ongoing (As additional evidence is collected, theories get revised.).and (2) it is collaborative (Scientists build on the work of those before them.) In addition, science requires creative thinking.

What is a paleontologist and why are they interested in knowing everything they can about creatures 500 million years old? An excellent reader-friendly book on this topic of putting together evolutionary history pieces and why we care is Your Inner Fish by Neil Shubin. Reviews are available from Discover magazine at http://discovermagazine.com/2008/feb/your-inner-fish

The following are some resources from the National Science Digital Library Middle School Portal: Structure and Function in Living Systems; Geologic Time: Eons, Eras and Epochs; and Have You Seen an Arthropod Lately?

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