SCIENCE
Notebook
Monday, December 4, 2006; Page A08
Ancient Fish Had Fiercest Bite
Sharks were not always the top predators in the ocean.
Dunkleosteus terrelli, an armored fish that grew up to 33 feet long and lived 400 million years ago, had jaws strong enough to bite a shark in two, according to research published last week in the journal Biology Letters.
  A Dunkleosteus terrelli fossil allowed scientists to build a model that reveals the fish's tremendous bite force, riving that of a Tyrannosaurus rex. (By Michael Labarbera -- The Field Museum) |
Scientists from the University of Chicago and the Field Museum created a biomechanical model of the skull of what they call the "Darth Vader of fishes" from a fossil that is on permanent exhibition at the museum.
The creature, one of various kinds of armored fishes known as placoderms that ruled aquatic ecosystems from 415 million to 360 million years ago, had the strongest bite ever for a fish, delivering a force of 8,000 pounds per square inch at the tip of its fangs. Its bite was strong enough to rival that of a Tyrannosaurus rex, and it allowed Dunkleosteus terrelli to snack on sharks and other tough-hided fish of the era. The model also demonstrates that the fish could open its jaws quickly, within a 50th of a second, creating suction that helped pull in its prey.
The fast and powerful jaws, made possible by four rotational joints working together, "made this fish into one of the true apex predators seen in the vertebrate fossil record," said Mark Westneat, curator of fishes at the museum and co-author of the study.
-- Christopher Lee
Climate May Threaten Penguins
The animated movie "Happy Feet" suggests that overfishing is imperiling penguins' survival, but a petition from an environmental advocacy group suggests that climate change poses a greater threat to the photogenic creatures.
In a petition filed last week, the Center for Biological Diversity asked the U.S. government to add 12 penguin species to the federal Endangered Species Act.
The group said unusually warm ocean temperatures have diminished the food available for penguins: The size of the Emperor penguin colony at Pointe Geologie, Antarctica, featured in the Oscar-winning documentary "March of the Penguins," dropped by half between 1952 and 2000, researchers found.
"These penguin species will march right into extinction unless greenhouse gas pollution is controlled," said the center's Kassie Siegel. "It is not too late to save them, but we must seize the available solutions to global warming immediately."
