Colette Giezentanner, speller 304, burst into laughter when she heard the sentence for her word, "oxyrhynch."
It's a crab having a pointed rostrum (the prolongation on the front central part of the shell).
Here's what the Missouri sixth grader found so funny: Keisha's book about the joys and perils of raising a spider crab in your apartment was called "There's an oxyrhynch in my sink."