By Christina Larson, scientific writer AP
Washington (AP) – Scientists in Australia have identified the oldest fossil fingerprints known to an animal similar to a reptile, dating from 350 million years.
The discovery suggests that after the first animals emerged from the ocean about 400 million years ago, they evolved the ability to live exclusively on land much faster than supposed previously.
“We had thought that the end transition to Limb took much more time,” said the paleontologist of California State University Stumida, who was not involved in the new research.
Previously, the first known reprints of reptiles, found in Canada, were dated 318 million years ago.
The old steps of Pas in Australia were found on a sandstone slab recovered near Melbourne and show feet of the reptile type with long toes and hooked claws.
Scientists estimate that the animal measured approximately 2 1/2 feet (80 centimeters) and may have looked like a modern monitor lizard. The results were published Wednesday in nature.
The hooked claws are a crucial identification index, said the co-author of the study and paleontologist by Ahlberg at the University of Uppsala in Sweden.
“It’s an animal that works,” he said.
Only animals that have evolved to live only on earth have ever developed claws. The first vertebrates – fish and amphibians – have never developed hard nails and remained dependent on the aqueous environments to lay the eggs and reproduce.
But the branch of the scalable tree which led to modern reptiles, birds and mammals – called Amniotes – has developed feet with nails or claws adapted to walking on a hard ground.
“This is the first proof that we have never seen an animal with claws,” said Sumida.
As the former reptile lived, the region was hot and hot and vast forests began to cover the planet. Australia was part of the Gondwana supercontinent.
Fossil fingerprints record a series of events in one day, Ahlberg said. A reptile climbed on the ground before a light rain falls. Some gout of rain has partially obscured its tracks. Then, two other reptiles passed in the opposite direction before the soil hardens and was covered with sediment.
The “fossil tracks are magnificent because they tell you how something lived, not just what something looked like,” said co-author John Long, paleontologist at Flinders University in Australia.
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Originally published:
California Daily Newspapers
