Fósseis mostram pegadas de animais mais antigas

Fossils Show Earliest Animal Trails

ScienceDaily (Feb. 3, 2010) — Trails found in rocks dating back 565 million years are thought to be the earliest evidence of animal locomotion ever found.

The newly-discovered fossils, from rocks in Newfoundland in Canada, were analysed by an international team led by Oxford University scientists. They identified over 70 fossilised trails indicating that some ancient creatures moved, in a similar way to modern sea anemones, across the seafloors of the Ediacaran Period.

Fossil showing 565 million-year-old animal trail. (Credit: Oxford University)

The team publish a report of their research in the February edition of the journal Geology.

'The markings we've found clearly indicate that these organisms could exert some sort of muscular control during locomotion,' said Alex Liu of Oxford University's Department of Earth Sciences, an author of the paper. 'This is exciting because it is the first evidence that creatures from this early period of Earth's history had muscles to allow them to move around -- enabling them to hunt for food or escape adverse local conditions and, importantly, indicating that they were probably animals.'

Scientists compared the trails to those left by the modern sea anemone Urticina, and found many similarities suggesting that the animals that made them were anemone-like -- perhaps using a muscular disc-shaped 'foot' to get around as anemones do today.

Evidence for animal movement from before the Cambrian Period (542-488 million years ago) is very rare, which has led many palaeontologists to suggest that earlier organisms were stationary and perhaps resembled modern fungi rather than animals.

...

Read more here/Leia mais aqui: Science Daily