Our understanding of how animals on the planet evolved may be wrong, according to scientists at the University of Bath.
Evolutionary biologists, from the university's department of biology and biochemistry, looked at nearly 100 fossil groups to test the notion that it takes groups of animals many millions of years to reach their maximum diversity of form.
And they found that, contrary to popular belief, not all animal groups continued to evolve fundamentally new morphologies through time.
In fact, the majority actually achieved their greatest diversity of form, or disparity, relatively early in their histories.
Lead researcher Dr Matthew Wills said: "This pattern, known as 'early high disparity', turns the traditional V-shaped cone model of evolution on its head.
"What is equally surprising in our findings is that groups of animals are likely to show early-high disparity regardless of when they originated over the last half a billion years."