Caption: California purple sea urchins are pictured in the rocky tide-pool hideaways that they carve with their teeth. New research by Pupa Gilbert, a physics professor at the University of Wisconsin-Madison, and her colleagues reveals how the sea urchin's teeth are always sharp, despite constant grinding and scraping to create the nooks that protect the marine animal from predators and crashing waves.
Photo: courtesy Pupa Gilbert
Date: 2010
High-resolution JPEG

Caption: A California purple sea urchin is pictured in hand. New research by Pupa Gilbert, a physics professor at the University of Wisconsin-Madison, and her colleagues reveals how the sea urchin's teeth are always sharp, despite constant grinding and scraping to create the nooks that protect the marine animal from predators and crashing waves.
Photo: courtesy Pupa Gilbert
Date: 2010
High-resolution JPEG

Caption: Sea urchin teeth are pictured in situ. New research by Pupa Gilbert, a physics professor at the University of Wisconsin-Madison, and her colleagues reveals how the sea urchin's teeth are always sharp, despite constant grinding and scraping to create the nooks that protect the marine animal from predators and crashing waves.
Photo: courtesy Pupa Gilbert
Date: 2010
High-resolution JPEG