July 13, 2007 — Similar diets have led to the evolution of similar snout shapes in a range of unrelated animals, say Australian researchers.
"Animals that had long skinny snouts tend to eat plants or small prey," says Dr Stephen Wroe of the University of New South Wales.
"Those with short broad snouts tended to be true carnivores and eat large prey."
Wroe, a palaeontologist with interest in biomechanics, says the findings are clear evidence of convergence, an important building block of evolutionary theory.
Convergent evolution is when unrelated animals independently evolve similar traits as a result of having to adapt to similar environmental problems, say eating raw meat.
Convergence can explain, for example, why the Tasmanian devil looks like a wolf when it's not at all related, says Wroe.
Wroe and Associate Professor Nicholas Milne of the University of Western Australia publish their findings in a recent issue of the journal Evolution.
Wroe and Milne used a computer program to build 3D skull models for a wide range of placental and marsupial mammals with a variety of diets, body sizes and shapes.
Animals ranged from the hyena and Australia's extinct marsupial lion to the bilby and the eastern quoll.
The skull models were designed to enable the researchers to compare key features of each skull, especially its length and breadth.
The results revealed an interesting relationship between diet and snout shape, with the shorter snouts more common in true carnivores that ate large prey and animals with long, narrow snouts tending to eat plants or smaller prey.
