Wednesday, November 29, 2006

Monster Fish Crushed Opposition With Strongest Bite Ever

Chomping champion ... The dunkleosteus measured up to 10 metres long, weighed 3600 kgs and had armour-plating around its head.

Chomping champion ... The dunkleosteus measured up to 10 metres long,
weighed 3600 kgs and had armour-plating around its head.
Photo: Reuters / Source: Sydney Morning Herald

Meet Dunkleosteus, a four-tonne, 10-metre, armour-plated fish that was arguably the first king of the beasts. The monstrous fish cruised the oceans [long] ago, preying on creatures much larger than itself, its blade-like fangs adept at tearing its quarry in two.
Using fossilised skull remains, scientists have built up a biomechanical model of the fish's powerful jaw and surrounding musculature, and they say it had the strongest bite of any fish ever to exist.
Philip Anderson's team at the University of Chicago found that the predator's jaws snapped shut with a force of more than five tonnes. The jaws were articulated by a unique mechanism based on four rotational joints working in harmony, they report in the Royal Society journal, Biology Letters, published yesterday.
Dunkleosteus was the first known large predator, pre-dating the dinosaurs. It belonged to a diverse group of armoured fish, placoderms, that dominated the oceans in the Devonian period. Its formidable bite allowed it to feast on other armoured aquatic animals, including primitive sharks and smaller creatures protected by bone-like casings. "Dunkleosteus was able to devour anything in its environment," Dr Anderson said.
While lacking true teeth, the fish used two long, bony blades in its mouth to snap and crush nearly any creature unfortunate enough to encounter it. The bladed jaws, which enabled the beast to take on prey much larger than its mouth, are a feature sharks did not develop until [much] later.
"It kind of blows sharks out of the water as far as bite force goes," Mark Westneat, the curator of fishes at the Field Museum of Natural History in Chicago and co-author of the paper, said. "A huge great white shark is probably only capable of biting at about half that force." He added: "The most interesting part of this work for me was discovering that this heavily-armoured fish was both fast during jaw-opening and quite powerful during jaw-closing. This is possible due to the unique engineering design of its skull and different muscles used for opening and closing. And it made this fish into one of the first true apex predators seen in the vertebrate fossil record."

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